2015 June 23
[ENERGY SIMULATION ]
Singapore June 2015 Energy
Simulation for Commercial Buildings
Singapore Energy Simulation for Commercial Buildings
Page ‐ 1 -
2015 June 22
[ENERGY SIMULATION]
Carrier Corporation
Software Systems Network
Carrier University
2003-2015Carrier Corporation
Carrier University
6540 Old Collamer Rd. S.
East Syracuse, NY 13057
World Wide Web: www.carrier.com/building-solutions/en/us
www.carrieruniversity.com
ALL RIGHTS RESERVED. No part of
this work covered by the copyright
hereon may be reproduced or used
in any form or by any means—
graphic, electronic, or mechanical,
including photocopying, recording,
taping, Web distribution or information
storage and retrieval systems—without
the written permission of Carrier Corporation.
For permission to use material from this text
contact us by:
Tel (800) 253-1794
Fax (315) 432.3871
e-Mail software.systems@carrier.utc.com
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 2 -
2015 June 22
[ENERGY SIMULATION]
Table of Contents
KEYS TO USING THIS TRAINING MANUAL ..................................................... - 7 ICONS USED IN THIS MANUAL ........................................................................ - 7 EARNING CEU CREDITS ................................................................................... - 8 Course Learning Outcomes .............................................................................................................. - 8 Continuing Education Unit Credits (CEUs) ..................................................................................... - 8 WELCOME TO ENERGY SIMULATION FOR COMMERCIAL BUILDINGS USING
HAP V4.9........................................................................................................... - 9 Workbook Organization .................................................................................................................... - 9 PROJECT DEFINITION AND OUTLINE ............................................................ - 10 SECTION 1_WORKSHOP 1 INPUTS - CREATE NEW PROJECT AND LINK
SIMULATION WEATHER ................................................................................. - 21 SETTING PROJECT PREFERENCES .......................................................................................................... - 21 ENTER DESIGN AND SIMULATION WEATHER PROPERTIES .................................................................... - 23 DEFINING THE HOLIDAY SCHEDULE ..................................................................................................... - 28 Weather Reports ............................................................................................................................. - 29 SECTION 1_WORKSHOP 2 – EDITING SCHEDULES ....................................... - 33 Schedule Profile Assignments Input Details ................................................................................... - 35 SECTION 2_WORKSHOP 3 - MODELING 4-PIPE FAN COIL UNIT AIR SYSTEMS USING THE EQUIPMENT WIZARD. ................................................................. - 43 SYSTEM DESIGN REPORTS ........................................................................................................................ 53
Zone Sizing Summary.......................................................................................................................... 54
Ventilation Sizing Summary ............................................................................................................ - 56 Air System Design Load Summary Report ...................................................................................... - 57 Hourly Zone Load Report Example ................................................................................................ - 58 SYSTEM SIMULATION REPORTS MONTHLY, DAILY AND HOURLY SIMULATION RESULTS .................... - 60 Monthly Air System Simulation Results .......................................................................................... - 60 Monthly Air System Simulation Graph ........................................................................................... - 61 Daily Air System Simulation Results ............................................................................................... - 62 Daily Air System Simulation Results ............................................................................................... - 64 Hourly Air System Simulation Results ............................................................................................ - 65 Hourly Air System Simulation Results Graph ................................................................................. - 67 Zone Temperature Report ............................................................................................................... - 68 SECTION 3_WORKSHOP 4 - MODELING CHILLERS, TOWERS, BOILERS AND
HYDRONIC PLANTS ............................................................................................ 71
Retrieve Energy Simulation Archive 2 Unsolved ................................................................................ 71
Air Cooled Chiller Selection ............................................................................................................... 75
Entering Chiller Performance Data................................................................................................ - 77 Cooling Plant Sizing Summary Comparison Discussion ................................................................ - 85 Entering Cooling Tower Performance Data ................................................................................... - 85 SECTION 4 ...................................................................................................... - 89 C Alt 2 Chiller Plant Input Data ..................................................................................................... - 94 D Alt3 SZCV/RTU ........................................................................................................................... - 95 Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 3 -
2015 June 22
[ENERGY SIMULATION]
SECTION 4_WORKSHOP 5 SOLUTIONS ......................................................... - 99 A Base Case Chiller Plant Simulation Results ................................................................................ - 99 D Alt 3 Packaged RTU D-31 RTU D5 Classroom D104 Simulation Results................................ - 105 SECTION 5_WORKSHOP 6 DEFINING AND SIMULATING BUILDINGS ......... - 111 Defining Buildings in HAP ........................................................................................................... - 111 SIMULATION RESULTS ................................................................................ - 119 Annual Emissions Summary .......................................................................................................... - 120 Annual Component Cost for C Alt 2 ............................................................................................. - 124 Annual Energy Cost ...................................................................................................................... - 125 Annual Cost HVAC and Non-HVAC ............................................................................................. - 126 Energy Budget by System Component........................................................................................... - 127 Energy Budget by Energy Source ................................................................................................. - 128 Monthly Component Cost ............................................................................................................. - 129 Monthly Energy Cost by Energy Type .......................................................................................... - 130 Monthly Energy Use by System Component ................................................................................. - 131 Monthly Energy Use by Energy Type............................................................................................ - 132 Electric Billing Details ................................................................................................................. - 133 Hourly Energy Use Profile ........................................................................................................... - 135 Hourly Energy Use Graph ............................................................................................................ - 136 APPENDIX “A”
AIR SYSTEM SCHEMATICS .............................................. - 139 -
APPENDIX”B” ............................................................................................... - 153 Putting Load Calculation Methods in Perspective ....................................................................... - 155 The Benefits of the Transfer Function / Heat Extraction Method ................................................. - 158 Understanding Zone Loads and Zone Conditioning ..................................................................... - 158 The Sizing Dilemma ...................................................................................................................... - 162 Which Sizing Method to Use? ....................................................................................................... - 163 Differences between Peak Coil Load CFM, Max Block CFM, Sum of Peak Zone CFM .............. - 165 Selecting Equipment When Coil CFM (L/s) Differ ....................................................................... - 168 ASHRAE 62.1-2004 and 2007 Ventilation Air Sizing in HAP ...................................................... - 169 ASHRAE Standard 62 ................................................................................................................... - 169 Defining ASHRAE Standard 62.1-2004/7 Ventilation Requirements in HAP ............................... - 170 Space Level Ventilation in ASHRAE 62.1-2004 & 2007 ............................................................... - 171 Space Usage Comparisons and Two-Part OA Requirement ......................................................... - 172 Step 1: Determining the Space Level Minimum Ventilation Requirements................................... - 174 Step 2: Determining the System Level Minimum Ventilation Requirements ................................. - 177 Minimum Supply Air (CFM) ......................................................................................................... - 180 Floor Area (sq ft) .......................................................................................................................... - 180 Required Outdoor Air (CFM/Ft²) ................................................................................................. - 180 Time Averaged Occupancy ........................................................................................................... - 180 Required Outdoor Air (CFM/Person) ........................................................................................... - 180 Air Distribution Effectiveness ....................................................................................................... - 180 Required Outdoor Air (CFM) ....................................................................................................... - 180 Uncorrected Outdoor Air (CFM) .................................................................................................. - 180 Space Ventilation Efficiency ......................................................................................................... - 181 Conclusion .................................................................................................................................... - 181 System Based Design Load Calculations ...................................................................................... - 182 APPENDIX “C” .............................................................................................. - 189 Technical White Papers ................................................................................................................ - 189 Introduction .................................................................................................................................. - 190 Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 4 -
2015 June 22
[ENERGY SIMULATION]
How Traditional System Design Methods Work ........................................................................... - 190 Shortcomings of the Traditional Approach ................................................................................... - 190 System-Based Design and How It Works ...................................................................................... - 191 Benefits of System-Based Design .................................................................................................. - 192 Conclusion .................................................................................................................................... - 192 The Benefits of 8760 Hour by Hour Building Energy Analysis..................................................... - 193 Introduction .................................................................................................................................. - 193 What Is Building Energy Analysis? .............................................................................................. - 193 Requirements for High Quality Results......................................................................................... - 193 8760 Hour-By-Hour Method: How and Why? .............................................................................. - 196 Conclusion .................................................................................................................................... - 199 LIST OF FIGURES
Figure 0.1 - Continuous Design Decision Cycle..........................................................- 10 Figure 0.2 – ASHRAE U.S. Climate Zone Map ...........................................................- 11 Figure 0.4 – School Exterior “A” Commons Area ........................................................- 12 Figure 0.5 – A Commons Area Floor Plan ..................................................................- 13 Figure 0.6 – “B” Classroom Wing ................................................................................- 14 Figure 0.7 – “C” – Gymnasium Wing...........................................................................- 15 Figure 0.8 – “D” Classroom Wing................................................................................- 16 Figure1.1 - Create New Project in HAP 4.9 ................................................................- 21 Figure1.2 – Setting Project Preferences .....................................................................- 22 Figure 1.3 – HAP Program Preferences
Figure1.4 – View/Preferences ....- 23 Figure 1.5 – HAP Weather Wizard ..............................................................................- 24 Figure 1.6 A, B & C – Weather Wizard Input Screens ................................................- 25 Figure 1.7 – Weather Wizard Design and Simulation Properties ................................- 25 Figure 1.8 – Wizard Created Data ..............................................................................- 26 Figure 1.9 - HAP Design Weather Properties Form. ...................................................- 26 Figure 1.10 – Importing Simulation Weather Data ......................................................- 27 Figure 1.11 – Adding Holidays ....................................................................................- 28 Figure 1.12 Design and Simulation Weather Reports .................................................- 29 Figure 2.1 - Schedule - Profile Assignments-Lights Classrooms ................................- 33 Figure 2.2 - Schedule–Profile Assignments-People-Classrooms ...............................- 34 Figure 3.1 - Launching the Equipment Wizard ............................................................- 43 Figure 3.2 - Assign Spaces to Building in Wizard .......................................................- 43 Figure 3.3a - Equipment Wizard Screen 1 ..................................................................- 44 Figure 3.3b - Equipment Wizard Screen 2 ..................................................................- 45 Figure 3.3c - Equipment Wizard Screen 2 ..................................................................- 46 Figure 3.3d - Equipment Wizard Screen 3 ..................................................................- 47 Figure 3.3e - Equipment and System Wizard Data Summary ....................................- 49 Figure 3.4 - Select Print View Design Reports ............................................................- 50 Figure 3.5 - Select Air System Sizing Summary Report .............................................- 50 Figure 3.6 - Select Simulation Results Reports ..........................................................- 58 Figure 3.7 - Select Air System Simulation Results Reports ........................................- 59 Figure 3.8 - Rerun and View all Air System Simulation Results .................................- 59 Figure 4.1 - Retrieve HAPv4.9 Energy Simulation Archive 2 Unsolved .......................... 71
Figure 4.2 - Create New Chiller Plant ............................................................................. 72
Figure 4.3 - Generic Chiller Plant Sizing Details ............................................................. 72
Figure 4.4 - Add “A Base Case” Air Systems to the Generic Chilled Water Plant .......... 73
Figure 4.5 - Calculate Chiller Plant Design Load ............................................................ 73
Figure 4.6 - Select Print/View Design Results – Cooling Plant Sizing Summary ............ 74
Figure 4.7 - Chiller Plant Sizing Summary Report .......................................................... 74
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 5 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.8 - Details of Chiller Selection using e-Cat Selection Software. ....................... 75
Figure 4.9a - Chiller Input Form – Import Chiller Data ................................................- 77 Figure 4.9b – Chiller Properties General Tab – Imported Chiller Data .......................- 78 Figure 4.9c - Chiller Properties Design Inputs – Imported Chiller Data ......................- 79 Figure 4.9d – Chiller Properties Performance Map – Imported Chiller Data ...............- 80 Figure 4.10 – Integrated Part Load Value ...................................................................- 81 Figure 4.11a – Define Chiller Part Load Performance ................................................- 82 Figure 4.11b – Chiller Template Design Inputs ...........................................................- 82 Figure 4.11c - Chiller Properties General Tab Template Data ....................................- 83 Figure 4.11d - Chiller Properties Design Inputs Tab ...................................................- 83 Figure 4.11e – Chiller Properties Performance Map Tab ............................................- 84 Figure 4.12 - Cooling Tower Properties for C Alt 2 WC Screw Chiller ........................- 86 Figure 4.13a Generic Service Hot Water Plant ...........................................................- 87 Figure 4.13b Link “A” Base Case Air Systems ............................................................- 87 Figure 4.13c –Define Service Hot Water Consumption ..............................................- 88 Figure 5.1 – Chiller Plants Created in WS4. ...............................................................- 91 Figure 5.2a – A Base Case Chiller Plant Data Inputs .................................................- 91 Figure 5.2b – A Base Case Air Systems .....................................................................- 92 Figure 5.2c – Base Case Plant Configuration .............................................................- 92 Figure 5.2d – Schedule of Equipment .........................................................................- 93 Figure 5.2e – Configure Plant Distribution ..................................................................- 93 Figure 5.3a – Packaged RTU-Configuration System Components –Supply Fan .......- 95 Figure 5.3b – Equipment – Central Cooling Unit.........................................................- 96 Figure 6.2 – Enter Building Data ..............................................................................- 114 Figure 6.3 – Assign Air Systems to Building Design .................................................- 114 Figure 6.4 – Misc. Energy Tab Input Details .............................................................- 115 Figure 6.5 – Building Meters Tab ..............................................................................- 116 Figure 6.6 – B Alt 1 Building Properties - Plants .......................................................- 116 Figure 6.7 – B Alt 1 Building Properties – Systems ..................................................- 116 Figure B-1. Load Estimating Methodologies ............................................................- 155 Figure B-2. Lighting Heat Gains and Loads ..............................................................- 156 Figure B-3 Stage One Calculations...........................................................................- 166 Figure B-4 Stage Two Calculations...........................................................................- 167 Figure C-1 Evolution of ASHRAE Ventilation Standards ..........................................- 169 Figure C-2 HAP Preferences ....................................................................................- 170 Figure C-3 Setting Project Preferences ....................................................................- 170 Figure C-4 HAP Space Properties Input Screen (General Tab) ...............................- 171 Figure C-5: Minimum Ventilation Rates ASHRAE 62.1-2004 ...................................- 171 Figure C-6: RETAIL Space Usage Comparison........................................................- 172 Figure C-7: EDUCATION Space Usage Comparison ...............................................- 173 Figure C-9 Space Air Distribution Effectiveness .......................................................- 176 Figure C-10 Typical VAV System and Critical Space ...............................................- 177 Figure C-11 No Critical Space Issues with Dedicated OA Unit .................................- 178 Figure C-12 Ventilation Report for VAV System .......................................................- 179 Figure D-1 VAV System Airflow Rates ......................................................................- 183 Figure D-2 Zone and Coil Load Profiles ....................................................................- 185 Figure D-3 Zone Air Temperature Profile ..................................................................- 186 Figure D-4 Loads for Varied Throttling Ranges ........................................................- 187 Figure D-5 Zone Temperatures for Varied Throttling Ranges...................................- 187 Figure E-1 Chicago Weather/September Dry Bulbs .................................................- 197 Figure E-2 Chicago Weather/September Solar.........................................................- 197 Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 6 -
[ENERGY SIMULATION]
2015 June 22
Keys to Using This Training Manual
Objectives - There is a listed of objectives at the beginning of each section.
Detailed discussions of materials for this section are included in the text.
Sample Section (Multiple Pages)
Objectives
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
___________________________________Step-by-step
Systematic exercises
preceded by topic
discussions, these
exercises are the “hands-onpractice” part of this section.
Summarize main points
at the end of each
section.
Review at the end of
each section ensures
achievement of
learning outcomes.
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
_________________________________________________
Summary
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
Review of Learning Outcomes
____________________________________________________
____________________________________________________
____________________________________________________
Enhanced screen shots included for additional detail
Icons Used in This Manual
Icon Key
Valuable Information
Learning Objective
Hands-on Exercise
The “icon key” at left depicts the four
icons used throughout this manual to
highlight valuable information, learning
outcome objectives, hands-on
exercises and additional information
included on the accompanying hand-
Additional Information on companion flash drive
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 7 -
[ENERGY SIMULATION]
2015 June 22
Earning CEU Credits
As part of our Technical Training Center, the International Associate for Continuing
Education and Training (IACET) accepts and approves the E20-II software training as an
Authorized Provider of Continuing Education Units (CEUs). IACET's mission is to
promote and enhance quality in continuing education and training through research,
education, and standard setting. IACET Authorized Providers undergo a strict evaluation
of their educational processes according to the IACET Criteria
and Guidelines, including two reviews by IACET's Commission
and a site visit by an IACET Commissioner. Members of the
organization are the educational professionals that strive to
provide the highest quality in continuing education and training.
Abstract
Energy Simulation is a term used to describe the process of energy modeling. Recently,
in the building industry the requirement for quality energy modeling has increased
dramatically. This is because of the rise in energy prices coupled with new specific
applications such as the LEED rating system, which places a large weighting on energy
fitness for both new and existing buildings. Quality energy simulation requires
consideration of many parameters such as simulation weather, energy profiles, air
systems, plant performance, utility rates and analysis of multiple building design
scenarios. The goal of this session is for each student to generate and interpret
simulations for air systems, plants, and whole buildings and produce accurate operating
cost comparison reports.
Course Learning Outcomes
As part of this software training, each student will learn how to use the Hourly Analysis
(System Design Load) Program by completing several simple project exercises. These
exercises confirm the student’s ability to understand the course learning outcomes.
These are:
 Define and input the following
o Energy simulation weather data, internal load schedules including profiles
used for energy analysis, unitary packaged equipment power
requirements, water chillers, boilers, cooling towers, hydronic distribution
systems, electric and fuel rate structures and miscellaneous building
energy use
 Generate and interpret simulation reports for air systems and plants
 Generate and interpret diagnostic reports for air systems and plants
 Trouble shoot air systems and plants
 Generate and interpret annual operating cost reports for a base and alternate
design case
 Determine best practices from energy simulation
Continuing Education Unit Credits (CEUs)
One (1) IACET CEU is equal to ten (10) contact hours of participation in an organized
continuing education experience under responsible sponsorship, capable direction, and
qualified instruction. After successfully completing this training, the student receives an
appropriate number of CEUs based on the classroom contact time. In addition, the
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 8 -
2015 June 22
[ENERGY SIMULATION]
student should feel very comfortable using the eDesign Suite software to enhance their
HVAC related job responsibilities.
We use this IACET symbol throughout this manual to represent required
learning outcomes and expect each student to comprehend the subject content
by successfully demonstrating competency in these areas.
NOTE: Because each state and municipality has their own rules, it is the responsibility
of the participants to determine whether their agency accepts IACET CEUs toward
whatever certification they are pursuing. This is not the responsibility of Carrier
Corporation or its agents.
Welcome to Energy Simulation for Commercial
Buildings using HAP v4.9
We created this manual to assist engineers and designers in using the Hourly Analysis
Program v4.9 for calculating commercial building cooling and heating loads and
performing energy simulations. This manual is a companion to the hands-on training for
the Hourly Analysis Program “Energy Simulations for Commercial Buildings” course
facilitated by Carrier Software Systems Network. This manual includes all class
exercises, workflow tips and additional helpful information related to the HAP program.
Workbook Organization
This section of the manual follows the logical process of the hands-on workshops and
workflow. We cover the common process and special features of the HAP program. We
arranged the topics of discussion in the same order as our hands-on training.
The second section discusses how to use HAP to calculate a system design load. The
second section follows the logical path of the program’s modules including detailed
discussions and examples of the workflow process used to create a complete HAP
Design Data set. This includes detailed discussions of the input forms, editing, document
outputs and more.
The third section of this student manual includes the following appendixes:
Appendix A includes air system schematics.
Appendix B contains detailed articles discussing numerous topics and frequently asked
questions about HAP inputs and results.
Appendix C includes several “white papers” discussing the advantages of the HAP
program. These include System Based Design and the use of 8760 hourly weather
profiles for calculations.
Appendix D includes HAP e Help articles offering detailed explanations on frequently
asked questions about HAP inputs and outputs.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 9 -
2015 June 22
[ENERGY SIMULATION]
Project Definition and Outline
Our project for this hands-on training is a 9-12 high school located in Singapore. There
are numerous workshops and work sessions requiring use and understanding of all
modules in the HAP program.
Workshop #1 includes configuring the weather data, adding simulation weather data and
defining annual holidays.
Workshop #2 requires updating fractional and fan-thermostat schedules by adding
profiles for assigning to the energy simulation of the buildings.
Workshop #3 includes defining air systems for the different building types for calculating
loads, selecting equipment, entering equipment performance, simulating the equipment
and analyzing the results.
In Workshop # 4 we calculate chiller and SWH boiler capacities, select and add chillers,
towers and SWH boilers to our project library.
In workshop # 5 we link the chillers, tower and SWH boilers to plants including
configuring the distribution and simulate the plant operations to compare plant energy
consumption for the different design scenarios.
In Workshop # 6 we add the utility rates to the project library. We discuss simple and
complex rate structures for electric, natural gas and remote source chilled and hot water.
We also look at the Utility Rate Time of Day schedule. We then define the different
building case studies, perform the energy simulation and compare the results; thus
enabling us to offer the best solution to the building owner and stake holders.
The objective of this projects is to provide a sustainable energy efficient 69,000 ft² (6,410
m²) one story high school building, with minimum carbon emissions. The target is to
reduce energy consumption while improving the built environment. Included in our
design project are recommended building envelope; fenestration optimized for
daylighting; interior and exterior lighting systems; HVAC systems and controls; OA
ventilation requirements and service water heating alternatives.
We use an integrated, iterative continuous design and construction decision process for
our building as shown in Figure 0.1 with the intention of fully coordinating best practices
for sustainable design throughout the life of the building (cradle-to-cradle) as follows.
Figure 0.1 - Continuous Design Decision Cycle
For our school building project we selected Singapore which is located in ASHRAE
Climate Zone 1A Hot and Moist, as detailed in the ASHRAE 90.1-2007 Appendix “B”.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 10 -
[ENERGY SIMULATION]
2015 June 22
Marine (C)
Dry (B)
Moist (A)
2
All of Alaska in Zone 7 except for the following
Boroughs in Zone 8:
Bethel
Northwest Artic
Dellingham
Southeast Fairbanks
Fairbanks
N. Star
Wade
Hampton
Nome
Yukon-Koyukuk
North Slope
1
Zone 1 Includes
Hawaii, Guam, Puerto Rico
and the Virgin Islands
Figure 0.2 – ASHRAE U.S. Climate Zone Map
The following pages include floor plans of the school building. This manual contains
detailed construction information for entering into the HAP program as needed for each
of the work sessions. This hands-on training session also leaves ample time for
participant question/answer sessions. Our goal is to make you familiar and comfortable
with the input routines and the calculated and simulated results of the HAP Design
Loads and Energy Simulation.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 11 -
2015 June 22
[ENERGY SIMULATION]
Figure 0.4 – School Exterior “A” Commons Area
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 12 -
2015 June 22
[ENERGY SIMULATION]
Figure 0.5 – A Commons Area Floor Plan
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 13 -
2015 June 22
[ENERGY SIMULATION]
Figure 0.6 – “B” Classroom Wing
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 14 -
2015 June 22
[ENERGY SIMULATION]
Figure 0.7 – “C” – Gymnasium Wing
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 15 -
2015 June 22
[ENERGY SIMULATION]
Figure 0.8 – “D” Classroom Wing
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 16 -
2015 June 22
[ENERGY SIMULATION]
We developed the school building construction using the ASHRAE Std. 90.1-2007
minimum envelope requirements and maximum “U” values for the building envelope
components for each climate zone. We did not follow the 90.1 Appendix “G” modeling
rules for our energy modeling. These requirements are covered in detail in our “Energy
Modeling for LEED EA Cr-1” training session.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 17 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 18 -
2015 June 22
[ENERGY SIMULATION]
Section 1
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 19 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 20 -
2015 June 22
[ENERGY SIMULATION]
Section 1_Workshop 1 Inputs - Create New Project and
Link Simulation Weather
Our first workshop focuses on expanding an existing design load analysis to include a
complete energy simulation. Our first step is retrieving an archived system design load
project developed in the Load Calculations for Commercial Buildings Training Seminar.
The retrieval of this project includes all spaces, air systems and library items so we can
focus on the additional input requirements for completing an energy analysis. Take the
following steps to begin this workshop.
First open windows explorer, navigate to folder B. Energy Simulation Student Handout
on the flash drive, copy folder 02. Unsolved Workshop Archives to your desktop.
Then launch HAP and create a new project as shown in Figure 1.1 below.
Figure1.1 - Create New Project in HAP 4.9
Setting Project Preferences
Once we create the New Project, HAP prompts us to choose the applicable ventilation
standard for the project. This first step in our design process links our project to the
appropriate database in determining the ventilation requirements for the spaces and air
systems in our project. The choices include:

User Defined

ASHRAE 62-2001

ASHRAE 62.1-2004
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 21 -
2015 June 22

ASHRAE 62.1-2007

ASHRAE 62.1-2010
[ENERGY SIMULATION]
After assigning the appropriate ventilation standard, we assign the appropriate Energy
Standard. The choices are:

ASHRAE 90.1-2004

ASHRAE 90.1-2007

ASHRAE 90.1-2010
Please refer to Fig 1.2 below for additional details.
Figure1.2 – Setting Project Preferences
Select the ASHRAE 62.1-2007 Ventilation Standard, ASHRAE 90.1-2007 Energy
Standard and Enter the appropriate Currency Symbol for our workshop and class
project.
Users can set HAP program preferences under the General Tab. Please refer to Figures
1.3 and 1.4 below for additional details of the General HAP program preferences.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 22 -
2015 June 22
[ENERGY SIMULATION]
Figure 1.3 – HAP Program Preferences
Figure1.4 – View/Preferences
Note: Users can access the Program Preferences anytime by going to the View item on
the menu bar and selecting Preferences as shown in Figure1.4
Retrieve Unsolved Archive 1 from B. Energy Simulation for Commercial Buildings/
Folder 02. Unsolved Archives/Singapore HAP49 EnergySim Unsolved Archive
1.E3A
Enter Design and Simulation Weather Properties
Next, we define the project design weather properties and link the 8760 hour simulation
weather file used in energy simulations, using one of the following methods. We can
assign the defaulted ASHRAE design weather properties by using the “Weather Wizard”
or using the Weather Properties input forms. Let’s first look at the Weather Wizard.
Go to the “Wizards” item on the menu bar and select “Weather Wizard.” When selecting
the weather wizard, HAP presents the following graphical interface where the user
selects the region, location and city either from the drop down or by clicking on the map.
Refer to Fig 1.5 and 1.6 below for details.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 23 -
2015 June 22
[ENERGY SIMULATION]
Figure 1.5 – HAP Weather Wizard
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 24 -
2015 June 22
[ENERGY SIMULATION]
Figure 1.6 A, B & C – Weather Wizard Input Screens
Once the user selects the Region, the next selection is Location. For our project, we
selected Asia/Pacific, Singapore and finally Singapore. This defaults to the ASHRAE
0.4% summer design conditions and 99.6% winter design conditions. This step also
automatically links the 8760 hourly simulation weather data. After selecting the weather
properties HAP generates the following Weather Wizard Input Summary as shown in
Figure 1.7.
Figure 1.7 – Weather Wizard Design and Simulation Properties
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 25 -
2015 June 22
[ENERGY SIMULATION]
After accepting the wizard inputs HAP converts the Wizard Data to the HAP interface as
shown in Figure 1.8.
Figure 1.8 – Wizard Created Data
Once the Wizard Data successfully converts to HAP data, the user can return to HAP
and edit any of the wizard created data by accessing the weather properties input forms
as shown in Figure 1.9.
Figure 1.9 - HAP Design Weather Properties Form.
Note that you can edit any of the input items in the Design Parameters, Design
Temperatures and Design Solar input forms. For our project, we accept the ASHRAE
defaults for St. Louis IAP, Missouri.
One of the major enhancements beginning with HAP 4.6 is the ability for users to import
the following simulation weather data formats: ASHRAE IWEC (*.IWEC), ASHRAE
IWEC2 (*.CSV), Energy Plus (*.EPW), USA TMY2 (*.TM2) or USA TMY3 (*.CSV). See
Figure 1.10 Below for additional details.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 26 -
2015 June 22
[ENERGY SIMULATION]
Figure 1.10 – Importing Simulation Weather Data
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 27 -
2015 June 22
[ENERGY SIMULATION]
Defining the Holiday Schedule
In the simulation input form under the simulation tab, configure energy simulation data
for the same city. The appropriate simulation weather for
Asia/Pacific_SINGAPORE_SINGAPORE_IWEC.HW1 linked when we used the wizard
to define the weather properties.
1. Let us Import Simulation Weather from the Flash Drive folder 02 Unsolved
Workshops as demonstrated.
2. Please change day of the week for January 1st to Thursday.
3. The next step is adding the following dates to the Holidays List by double left
clicking the date on the calendar:
4. Use the Navigation buttons to change calendar month
Holiday List
16-20 March
1-5, 8-12, 15-19, 22-26 June
04, 07-11 September
23-27, 30 November
These dates represent typical secondary
school holidays. We model the winter break
in the fractional schedules for internal loads
and energy use.
Figure 1.11 – Adding Holidays
Note: Please remember to “save early and save often”
Design and simulation weather reports are displayed on the following pages.
Use one of the following procedures to preview the weather input details.
1. Weather reports are available by highlighting “weather” in the left tree then left clicking
on “Reports” and choosing “Print/View Input Data”
or
2. Right click on < Weather Properties> and choose “Print/View Input Data”.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 28 -
2015 June 22
[ENERGY SIMULATION]
Select the weather reports shown in Figure 1.12 below. HAP uses “Design” weather data
in determining peak heating and cooling load calculations and sizing coils, fans and
terminal equipment. HAP uses the 8760 hourly “Simulation” weather data to simulate
building energy consumption and calculating annual operating cost based on the
equipment sized and selected using the design weather data.
Figure 1.12 Design and Simulation Weather Reports
Below are just a few examples of the available weather reports.
Weather Reports
Design Parameters:
City Name ...................................................................................................... Singapore
Location ......................................................................................................... Singapore
Latitude ...................................................................................................................... 1.4
Longitude .............................................................................................................. -104.0
Elevation .................................................................................................................. 52.0
Summer Design Dry-Bulb ........................................................................................ 91.0
Summer Coincident Wet-Bulb .................................................................................. 79.0
Summer Daily Range ............................................................................................... 11.3
Winter Design Dry-Bulb ............................................................................................ 73.0
Winter Design Wet-Bulb ........................................................................................... 60.9
Atmospheric Clearness Number .............................................................................. 1.00
Average Ground Reflectance ................................................................................... 0.20
Soil Conductivity .................................................................................................... 0.800
Local Time Zone (GMT +/- N hours) ......................................................................... -8.0
Consider Daylight Savings Time ................................................................................ No
Simulation Weather Data ................................................................ SINGAPORE (EXT)
Current Data is ...................................................................... 2001 ASHRAE Handbook
Design Cooling Months ............................................................... January to December
Singapore 2015 Energy Simulation for Commercial Buildings
Deg.
Deg.
ft
°F
°F
°F
°F
°F
BTU/(hr-ft-°F)
hours
Page ‐ 29 -
2015 June 22
[ENERGY SIMULATION]
Design Day Maximum Solar Heat Gains
Month
January
February
March
April
May
June
July
August
September
October
November
December
Month
January
February
March
April
May
June
July
August
September
October
November
December
(The MSHG values are expressed in BTU/(hr-ft²) )
N
NNE
NE
ENE
34.0
34.0
82.9
172.4
35.3
35.7
126.4
201.2
37.9
82.4
166.6
220.2
64.6
132.3
192.8
223.1
105.3
160.3
205.5
220.2
122.0
168.1
207.4
216.6
108.1
158.4
202.0
216.4
68.8
131.8
188.8
217.0
39.3
79.3
157.5
207.5
35.9
36.9
125.5
193.8
34.2
34.2
86.6
170.4
33.0
33.0
69.7
156.0
SSW
SW
WSW
W
187.0
234.5
249.3
229.7
144.9
209.5
245.0
242.4
88.4
169.5
221.0
238.2
38.8
116.6
182.0
218.2
37.1
80.4
153.5
201.8
37.3
67.0
138.8
191.5
37.9
78.5
146.3
194.7
39.6
110.6
174.0
209.8
88.1
165.1
212.9
228.6
140.6
205.6
238.1
234.3
182.2
233.8
249.5
226.7
199.1
243.4
250.4
218.8
E
230.9
242.8
240.2
219.8
202.0
193.4
198.3
212.8
226.2
231.2
223.6
220.8
WNW
174.2
202.1
218.8
221.8
220.1
215.6
214.2
214.7
209.7
194.7
169.1
158.5
ESE
253.9
247.0
223.3
183.6
153.7
141.5
151.0
177.0
210.9
232.8
245.2
251.8
NW
86.8
129.1
165.5
192.1
205.4
207.6
202.1
187.8
159.2
123.0
83.9
70.1
SE
237.5
213.0
172.4
117.4
80.2
65.3
77.7
112.9
163.8
202.5
232.2
243.8
NNW
34.0
36.1
82.1
132.2
160.4
169.1
160.3
132.0
80.2
36.9
34.2
33.0
SSE
184.5
145.3
90.3
38.9
37.1
37.3
37.9
39.6
87.6
140.8
183.9
198.4
HOR
292.0
303.8
302.0
283.1
265.2
256.1
261.3
275.9
291.3
296.6
288.7
282.4
Mult. = User-defined solar multiplier factor.
The Design Solar tab contains information about solar heat gain profiles for the currently
selected city. Based on the design parameters for the city you selected, HAP constructs
24-hour profiles of solar flux and solar heat gain for all 12 months using ASHRAE
procedures. Each profile represents clear sky solar conditions. Solar profiles are used
for wall, roof and window load calculations.
Singapore 2015 Energy Simulation for Commercial Buildings
Page ‐ 30 -
S
126.4
74.1
38.8
37.6
37.1
37.3
37.9
39.1
40.3
72.6
124.4
145.5
Mult
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
2015 June 22
[ENERGY SIMULATION]
Location: Singapore, Singapore
(Dry and Wet Bulb temperatures are expressed in °F)
Hr
January
February
March
DB
WB
DB
WB
DB
WB
0000
71.7
69.9
73.7
71.4
76.7
73.5
0100
71.2
69.7
73.2
71.2
76.2
73.4
0200
70.6
69.5
72.6
71.1
75.6
73.2
0300
70.2
69.4
72.2
70.9
75.2
73.1
0400
69.8
69.2
71.8
70.9
74.8
73.0
0500
69.7
69.2
71.7
70.8
74.7
73.0
0600
69.9
69.3
71.9
70.9
74.9
73.0
0700
70.5
69.5
72.5
71.0
75.5
73.2
0800
71.5
69.8
73.5
71.3
76.5
73.5
0900
73.0
70.3
75.0
71.8
78.0
73.8
1000
74.7
70.9
76.7
72.2
79.7
74.3
1100
76.6
71.6
78.6
72.8
81.6
74.8
1200
78.4
72.2
80.4
73.3
83.4
75.3
1300
79.8
72.6
81.8
73.7
84.8
75.7
1400
80.7
72.9
82.7
73.9
85.7
75.9
1500
81.0
73.0
83.0
74.0
86.0
76.0
1600
80.7
72.9
82.7
73.9
85.7
75.9
1700
79.9
72.6
81.9
73.7
84.9
75.7
1800
78.6
72.2
80.6
73.3
83.6
75.4
1900
77.2
71.7
79.2
72.9
82.2
75.0
2000
75.7
71.3
77.7
72.5
80.7
74.6
2100
74.4
70.8
76.4
72.2
79.4
74.3
2200
73.3
70.5
75.3
71.9
78.3
74.0
2300
72.4
70.1
74.4
71.6
77.4
73.7
Hr
July
August
September
DB
WB
DB
WB
DB
WB
0000
81.7
76.7
81.7
76.7
79.7
75.6
0100
81.2
76.5
81.2
76.5
79.2
75.5
0200
80.6
76.4
80.6
76.4
78.6
75.3
0300
80.2
76.3
80.2
76.3
78.2
75.2
0400
79.8
76.2
79.8
76.2
77.8
75.1
0500
79.7
76.1
79.7
76.1
77.7
75.1
0600
79.9
76.2
79.9
76.2
77.9
75.1
0700
80.5
76.3
80.5
76.3
78.5
75.3
0800
81.5
76.6
81.5
76.6
79.5
75.6
0900
83.0
77.0
83.0
77.0
81.0
75.9
1000
84.7
77.4
84.7
77.4
82.7
76.4
1100
86.6
77.9
86.6
77.9
84.6
76.9
1200
88.4
78.4
88.4
78.4
86.4
77.3
1300
89.8
78.7
89.8
78.7
87.8
77.7
1400
90.7
78.9
90.7
78.9
88.7
77.9
1500
91.0
79.0
91.0
79.0
89.0
78.0
1600
90.7
78.9
90.7
78.9
88.7
77.9
1700
89.9
78.7
89.9
78.7
87.9
77.7
1800
88.6
78.4
88.6
78.4
86.6
77.4
1900
87.2
78.0
87.2
78.0
85.2
77.0
2000
85.7
77.7
85.7
77.7
83.7
76.7
2100
84.4
77.4
84.4
77.4
82.4
76.3
2200
83.3
77.1
83.3
77.1
81.3
76.0
2300
82.4
76.8
82.4
76.8
80.4
75.8
Singapore 2015 Energy Simulation for Commercial Buildings
April
DB
WB
77.7
74.6
77.2
74.4
76.6
74.3
76.2
74.1
75.8
74.1
75.7
74.0
75.9
74.1
76.5
74.2
77.5
74.5
79.0
74.9
80.7
75.4
82.6
75.9
84.4
76.3
85.8
76.7
86.7
76.9
87.0
77.0
86.7
76.9
85.9
76.7
84.6
76.4
83.2
76.0
81.7
75.6
80.4
75.3
79.3
75.0
78.4
74.8
October
DB
WB
77.7
74.6
77.2
74.4
76.6
74.3
76.2
74.1
75.8
74.1
75.7
74.0
75.9
74.1
76.5
74.2
77.5
74.5
79.0
74.9
80.7
75.4
82.6
75.9
84.4
76.3
85.8
76.7
86.7
76.9
87.0
77.0
86.7
76.9
85.9
76.7
84.6
76.4
83.2
76.0
81.7
75.6
80.4
75.3
79.3
75.0
78.4
74.8
May
DB
WB
78.7
75.6
78.2
75.5
77.6
75.3
77.2
75.2
76.8
75.1
76.7
75.1
76.9
75.1
77.5
75.3
78.5
75.6
80.0
75.9
81.7
76.4
83.6
76.9
85.4
77.3
86.8
77.7
87.7
77.9
88.0
78.0
87.7
77.9
86.9
77.7
85.6
77.4
84.2
77.0
82.7
76.7
81.4
76.3
80.3
76.0
79.4
75.8
November
DB
WB
74.7
72.9
74.2
72.7
73.6
72.5
73.2
72.4
72.8
72.2
72.7
72.2
72.9
72.3
73.5
72.5
74.5
72.8
76.0
73.3
77.7
73.9
79.6
74.6
81.4
75.2
82.8
75.6
83.7
75.9
84.0
76.0
83.7
75.9
82.9
75.6
81.6
75.2
80.2
74.7
78.7
74.3
77.4
73.8
76.3
73.5
75.4
73.1
June
DB
WB
80.7
76.7
80.2
76.5
79.6
76.4
79.2
76.3
78.8
76.2
78.7
76.1
78.9
76.2
79.5
76.4
80.5
76.6
82.0
77.0
83.7
77.4
85.6
77.9
87.4
78.4
88.8
78.7
89.7
78.9
90.0
79.0
89.7
78.9
88.9
78.7
87.6
78.4
86.2
78.0
84.7
77.7
83.4
77.4
82.3
77.1
81.4
76.8
December
DB
WB
72.7
70.9
72.2
70.7
71.6
70.5
71.2
70.4
70.8
70.2
70.7
70.2
70.9
70.3
71.5
70.5
72.5
70.8
74.0
71.3
75.7
71.9
77.6
72.6
79.4
73.2
80.8
73.6
81.7
73.9
82.0
74.0
81.7
73.9
80.9
73.6
79.6
73.2
78.2
72.7
76.7
72.3
75.4
71.8
74.3
71.5
73.4
71.1
Page ‐ 31 -
[ENERGY SIMULATION]
2015 June 22
Simulation Weather Profile for August 27
Wednesday, August 27
Hour
Dry-Bulb
( °F )
Wet-Bulb
( °F )
0000
0100
0200
0300
0400
0500
0600
0700
0800
0900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
78.8
78.3
78.8
77.0
77.9
77.0
77.0
77.9
80.6
82.4
83.5
86.0
84.2
86.0
87.8
89.6
89.1
87.8
86.0
84.2
82.4
80.6
81.1
80.6
76.2
75.1
75.0
75.8
75.5
75.8
75.8
75.1
76.7
77.1
76.3
76.8
78.9
78.5
79.8
77.8
77.5
76.2
76.9
76.4
77.2
76.7
77.1
76.7
Singapore 2015 Energy Simulation for Commercial Buildings
Beam Solar
on Horiz.
( BTU/(hr-ft²) )
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
6.6
17.9
28.3
81.1
126.9
156.9
170.5
152.1
110.2
38.1
1.3
0.0
0.0
0.0
0.0
0.0
Total Solar
on Horiz.
( BTU/(hr-ft²) )
0.0
0.0
0.0
0.0
0.0
0.0
0.0
6.3
49.1
103.5
152.2
212.0
254.0
272.6
262.7
226.6
165.0
86.0
17.5
0.0
0.0
0.0
0.0
0.0
Page ‐ 32 -
2015 June 23
[ENERGY SIMULATION ]
Section 1_Workshop 2 – Editing Schedules
This workshop focuses on editing the previously created schedules from our system
design load calculations and were included in the retrieved archive. Please add the
following hourly profiles to each schedule as noted:
Lights - Classrooms
Profile #4 – Energy Weekday
Hours 00-06: 05%
07: 25%
08-11: 90%
12: 05%
13-15: 90%
16: 40%
17-23: 05%
Profile #5 – Energy Weekend
Hours 00-23: 05%
On the Assignments tab, assign Profile #4 to Monday thru Friday in all months except
December. Assign existing Profile #2 from the design load phase to Monday thru
Friday in the month of June only. Assign existing Profile #3 to Monday thru Holiday
for the month of July only.
Assign Profile #5 to day types Saturday, Sunday, and Holiday for all months. Refer to
Figure 2.1 for additional details.
Figure 2.1 - Schedule - Profile Assignments-Lights Classrooms
Singapore Energy Simulation for Commercial Buildings
Page ‐ 33 -
2015 June 22
[ENERGY SIMULATION]
People - Classrooms
Profile #4 – Energy Weekday
Hours 00-06: 00%
Hour
07: 10%
Hours 08-11: 90%
Hour
12: 10%
Hours 13-15: 90%
Hour
16: 25%
Hour
17: 10%
Hours 18-23: 00%
Profile #5 – Energy Saturday
Hours 00-07: 00%
Hours 08-12: 10%
Hours 13-23: 00%
On the Assignments tab, assign Profile #4 to day types Monday thru Friday in all
months except June and December. Assign Profile #3 to day types Monday through
Friday for June and December only and Profile #3 to Sunday thru Holiday in all
months except December.
Assign Profile #5 to day type Saturday for all months except June and December.
Refer to Figure 2.2 for details.
Figure 2.2 - Schedule–Profile Assignments-People-Classrooms
Energy Simulation for Commercial Buildings
Page ‐ 34 -
[ENERGY SIMULATION]
2015 June 22
The remaining schedules were completed and included in the retrieved archive.
They are shown below for reference only.
Schedule Profile Assignments Input Details
Lights - Classrooms (Fractional)
Hourly Profiles:
1:Design Day
Hour
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Value
10
10
10
10
10
10
10
10
100 100 100 100 100 100 100 100
30
10
10
10
10
10
10
10
2:Summer School
Hour
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Value
5
5
5
5
5
5
5
5
60
60
60
60
60
25
5
5
5
5
5
5
5
5
5
5
3:Summer Shutdown
Hour
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Value
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
4:Energy Weekdays
Hour
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Value
5
5
5
5
5
5
5
25
90
90
90
90
5
90
90
90
40
5
5
5
5
5
5
5
5:Energy Weekends
Hour
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Value
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Assignments:
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Design
1
1
1
1
1
2
3
1
1
1
1
1
Monday
4
4
4
4
4
2
3
4
4
4
4
4
Tuesday
4
4
4
4
4
2
3
4
4
4
4
4
Wednesday
4
4
4
4
4
2
3
4
4
4
4
4
Thursday
4
4
4
4
4
2
3
4
4
4
4
4
Friday
4
4
4
4
4
2
3
4
4
4
4
4
Saturday
5
5
5
5
5
5
5
5
5
5
5
5
Sunday
5
5
5
5
5
5
5
5
5
5
5
5
Holiday
5
5
5
5
5
5
5
5
5
5
5
5
Energy Simulation for Commercial Buildings
Page ‐ 35 -
[ENERGY SIMULATION]
2015 June 22
People - Classrooms (Fractional)
Hourly Profiles:
1:Design Day
Hour 00
Value 0
01
0
02
0
03
0
04
0
05
0
06
0
07
5
08 09 10 11 12 13 14 15
100 100 100 100 100 100 100 100
16
40
17
10
18
0
19
0
20
0
21
0
22
0
23
0
2:Summer School
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
0
08
40
09
40
10
40
11
40
12
40
13
10
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
3:Summer Shutdown
Hour 00 01 02
Value 0
0
0
03
0
04
0
05
0
06
0
07
0
08
0
09
0
10
0
11
0
12
0
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
4:Weekday Energy
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
10
08
90
09
90
10
90
11
90
12
10
13
90
14
90
15
90
16
25
17
10
18
0
19
0
20
0
21
0
22
0
23
0
5:Energy Saturday
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
0
08
10
09
10
10
10
11
10
12
10
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
Assignments:
Design
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Holiday
Jan
1
4
4
4
4
4
5
3
3
Feb
1
4
4
4
4
4
5
3
3
Mar
1
4
4
4
4
4
5
3
3
Energy Simulation for Commercial Buildings
Apr
1
4
4
4
4
4
5
3
3
May
1
4
4
4
4
4
5
3
3
Jun
3
3
3
3
3
3
3
3
3
Jul
1
4
4
4
4
4
5
3
3
Aug
1
4
4
4
4
4
5
3
3
Sep
1
4
4
4
4
4
5
3
3
Oct
1
4
4
4
4
4
5
3
3
Nov
1
4
4
4
4
4
5
3
3
Page ‐ 36 -
Dec
3
3
3
3
3
3
3
3
3
[ENERGY SIMULATION]
2015 June 22
People - Corridors (Fractional)
Hourly Profiles:
1:Design Day
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
50
08 09 10 11 12 13 14 15
100 100 100 100 100 100 100 100
16
30
17
10
18
0
19
0
20
0
21
0
22
0
23
0
2:Summer School
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
0
08
40
09
40
10
40
11
40
12
40
13
40
14
10
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
3:Summer Shutdown
Hour 00 01 02
Value 0
0
0
03
0
04
0
05
0
06
0
07
0
08
0
09
0
10
0
11
0
12
0
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
4:Weekday Energy
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
25
08
50
09
40
10
40
11
45
12
60
13
45
14
40
15
40
16
25
17
10
18
0
19
0
20
0
21
0
22
0
23
0
5:Energy Weekends
Hour 00 01 02
Value 0
0
0
03
0
04
0
05
0
06
0
07
0
08
0
09
0
10
0
11
0
12
0
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
Assignments:
Design
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Holiday
Jan
1
4
4
4
4
4
5
5
5
Feb
1
4
4
4
4
4
5
5
5
Mar
1
4
4
4
4
4
5
5
5
Energy Simulation for Commercial Buildings
Apr
1
4
4
4
4
4
5
5
5
May
1
4
4
4
4
4
5
5
5
Jun
5
5
5
5
5
5
5
5
5
Jul
1
4
4
4
4
4
5
5
5
Aug
1
4
4
4
4
4
5
5
5
Sep
1
4
4
4
4
4
5
5
5
Oct
1
4
4
4
4
4
5
5
5
Nov
1
4
4
4
4
4
5
5
5
Page ‐ 37 -
Dec
5
5
5
5
5
5
5
5
5
[ENERGY SIMULATION]
2015 June 22
People IT Room (Fractional)
Hourly Profiles:
1:Design Day
Hour 00 01
Value 0
0
02
0
03
0
04
0
05
0
06
0
07
10
08
100
09
0
10
0
11
0
12
100
13
0
14
0
15
100
16
0
17
10
18
0
19
0
20
0
21
0
22
0
23
0
2:Summer School
Hour 00 01 02
Value 0
0
0
03
0
04
0
05
0
06
0
07
0
08
0
09
40
10
0
11
0
12
40
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
3:Summer Shutdown
Hour 00 01 02
Value 0
0
0
03
0
04
0
05
0
06
0
07
0
08
0
09
0
10
0
11
0
12
0
13
0
14
0
15
0
16
0
17
0
18
0
19
0
20
0
21
0
22
0
23
0
Assignments:
Design
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Holiday
Jan
1
1
1
1
1
1
3
3
3
Feb
1
1
1
1
1
1
3
3
3
Mar
1
1
1
1
1
1
3
3
3
Apr
1
1
1
1
1
1
3
3
3
May
1
1
1
1
1
1
3
3
3
Jun
3
3
3
3
3
3
3
3
3
Jul
1
1
1
1
1
1
3
3
3
Aug
1
1
1
1
1
1
3
3
3
Sep
1
1
1
1
1
1
3
3
3
Oct
1
1
1
1
1
1
3
3
3
Nov
1
1
1
1
1
1
3
3
3
Dec
3
3
3
3
3
3
3
3
3
Equipment IT (Fractional)
Hourly Profiles:
1:design
Hour 00 01
Value 25 25
02
25
03
25
04
25
05
25
06
25
07
80
08
80
09
50
10
50
11
50
12
80
13
70
14
60
15
50
16
80
17
50
18
25
19
25
20
25
21
25
22
25
23
25
2:Summer
Hour 00
Value 25
02
25
03
25
04
25
05
25
06
25
07
25
08
25
09
25
10
25
11
25
12
25
13
25
14
25
15
25
16
25
17
25
18
25
19
25
20
25
21
25
22
25
23
25
01
25
Assignments:
Design
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Holiday
Jan
1
1
1
1
1
1
2
2
2
Feb
1
1
1
1
1
1
2
2
2
Mar
1
1
1
1
1
1
2
2
2
Energy Simulation for Commercial Buildings
Apr
1
1
1
1
1
1
2
2
2
May
1
1
1
1
1
1
2
2
2
Jun
2
2
2
2
2
2
2
2
2
Jul
2
2
2
2
2
2
2
2
2
Aug
1
1
1
1
1
1
2
2
2
Sep
1
1
1
1
1
1
2
2
2
Oct
1
1
1
1
1
1
2
2
2
Nov
1
1
1
1
1
1
2
2
2
Page ‐ 38 -
Dec
2
2
2
2
2
2
2
2
2
[ENERGY SIMULATION]
2015 June 22
Occupied Schedule - Classroom (Fan / Thermostat)
Hourly Profiles:
1:Design Day
Hour 00 01
Value U
U
02
U
03
U
04
U
05
U
06
O
07
O
08
O
09
O
10
O
11
O
12
O
13
O
14
O
15
O
16
O
17
O
18
U
19
U
20
U
21
U
22
U
23
U
2:Summer School
Hour 00 01
Value U
U
02
U
03
U
04
U
05
U
06
O
07
O
08
O
09
O
10
O
11
O
12
O
13
O
14
U
15
U
16
U
17
U
18
U
19
U
20
U
21
U
22
U
23
U
3:Summer Shutdown
Hour 00 01 02
Value U
U
U
03
U
04
U
05
U
06
U
07
U
08
U
09
U
10
U
11
U
12
U
13
U
14
U
15
U
16
U
17
U
18
U
19
U
20
U
21
U
22
U
23
U
4:Energy Weekdays
Hour 00 01 02
Value U
U
U
03
U
04
U
05
U
06
O
07
O
08
O
09
O
10
O
11
O
12
O
13
O
14
O
15
O
16
O
17
O
18
U
19
U
20
U
21
U
22
U
23
U
5:Energy Saturday
Hour 00 01
Value U
U
03
U
04
U
05
U
06
U
07
O
08
O
09
O
10
O
11
O
12
O
13
U
14
U
15
U
16
U
17
U
18
U
19
U
20
U
21
U
22
U
23
U
02
U
O = Occupied; U = Unoccupied
Assignments:
Design
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Holiday
Jan
1
4
4
4
4
4
2
3
3
Feb
1
4
4
4
4
4
2
3
3
Mar
1
4
4
4
4
4
2
3
3
Energy Simulation for Commercial Buildings
Apr
1
4
4
4
4
4
2
3
3
May
1
4
4
4
4
4
2
3
3
Jun
3
3
3
3
3
3
2
3
3
Jul
1
4
4
4
4
4
2
3
3
Aug
1
4
4
4
4
4
2
3
3
Sep
1
4
4
4
4
4
2
3
3
Oct
1
4
4
4
4
4
2
3
3
Nov
1
4
4
4
4
4
2
3
3
Page ‐ 39 -
Dec
3
3
3
3
3
3
2
3
3
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 40 -
[ENERGY SIMULATION]
2015 June 22
Section 2
Energy Simulation for Commercial Buildings
Page ‐ 41 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 42 -
2015 June 22
[ENERGY SIMULATION]
Section 2_Workshop 3 - Modeling 4-Pipe Fan Coil Unit
Air Systems - Using the Equipment Wizard.
Launch the Equipment Wizard by selecting the Wizard item on the Menu bar and clicking
the Equipment Wizard on the list. See Figure 3.1 for details.
Figure 3.1 - Launching the Equipment Wizard
Next add the following spaces top the system. Assign spaced D100 through D114 to the
building and click OK. Refer to Figure 3.2 for additional details.
Figure 3.2 - Assign Spaces to Building in Wizard
After assigning the spaces the following screen appears. Enter the system and
equipment data as described below and detailed in the following figures.
Energy Simulation for Commercial Buildings
Page ‐ 43 -
2015 June 22
[ENERGY SIMULATION]
Figure 3.3a - Equipment Wizard Screen 1
1.
2.
3.
4.
5.
6.
7.
8.
9.
Enter Air System Name and Identifier
Select 4 Pipe Hydronic Fan Coil Units from Equipment Type dropdown
Select Hot Water from the Heating Type dropdown
Select Fan Coil Units from the System Type dropdown
Select One FCU per Zone from the Configuration dropdown
Select Occupied Schedule-Classroom from the Operating Schedule dropdown
Select CW Ventilation Unit from the Common Vent Unit dropdown
Select Used from the DCV Control dropdown
Select Energy Recovery Ventilator (ERV) from the Ventilation Reclaim dropdown
Now click on the Details Button and enter the details as shown in Fig 3.3b.
Energy Simulation for Commercial Buildings
Page ‐ 44 -
2015 June 22
[ENERGY SIMULATION]
Figure 3.3b - Equipment Wizard Screen 2
1. Enter the FCU Design SAT 58ºF Cooling and 90ºF Heating
2. Enter Terminal Unit Supply Fan Performance 0.50” wg.
3. Accept T-stat Occ/Unocc Setpoints 75º/80º F [23.89º/26.67º C] Clg and 70º/65º F
[21.1º/18.3º C] Htg.
4. Accept the Operating Schedule using the T-Stat Schedule - Classrooms
5. Enter the Common Vent Unit Cooling and Heating Coil Setpoint 75º/70º F
[23.89º/21.1ºC]
6. Enter the Ventilation and Exhaust fan performance of 1.50”/1.00” wg
respectively.
7. Configure the DCV Base Ventilation Rate 20%, 257ppm Min. CO2, 700ppm Max
CO2 differentials and 393ppm Outdoor Air CO2 levels
8. Enter 50% Ventilation Reclaim Efficiency and 0.200kW Input Power
9. Click OK when finished.
10. Click Next Button
Because we are only analyzing the Wing D 4 Pipe FCU air system, we can just accept
the chiller and boiler plant defaults which we will discard. The next two screens depict
the chiller and boiler plant wizard input forms and are for reference only.
Energy Simulation for Commercial Buildings
Page ‐ 45 -
2015 June 22
[ENERGY SIMULATION]
Figure 3.3c - Equipment Wizard Screen 2
Click on the Next button and enter the data detailed in Figure 3.3d
Energy Simulation for Commercial Buildings
Page ‐ 46 -
2015 June 22
[ENERGY SIMULATION]
Figure 3.3d - Equipment Wizard Screen 3
Click Finish. Clicking the Finish button generates the following Equipment Wizard input
report. Please refer to the details in Figure 3.3e below.
Energy Simulation for Commercial Buildings
Page ‐ 47 -
2015 June 22
[ENERGY SIMULATION]
EQUIPMENT ALTERNATIVE: (C8-FCU) 4 Pipe Fan Coil Units
Equipment and System Data Summary
Description
Name ...................................................................... 2P FCU
Identifier .................................................................. 2P FCU
Notes .....................................................................................
Equipment
Equipment Type ............................... 2-Pipe Fan Coil Units
Heating Type ............................................................... None
System Type ................................................ Fan Coil Units
Configuration ......................................... One FCU per Zone
Operating Schedule ............ T-Stat Schedule - Classroom
Key Features
Common Ventilation Unit .................... CW Ventilation Unit
Demand Controlled Ventilation .................................... Used
Ventilation Reclaim ..... Energy Recovery Ventilator (ERV)
Equipment and System Details
Terminal Unit Cooling
Design SAT ................................................................... 58.0 °F
Terminal Unit Features
Supply Fan Performance .............................................. 0.50 in wg
Thermostats
Cooling Setpoint, Occupied ........................................... 75.0
Cooling Setpoint, Unoccupied ....................................... 80.0
Heating Setpoint, Occupied ........................................... 70.0
Heating Setpoint, Unoccupied ....................................... 65.0
Operating Schedule ............ T-Stat Schedule - Classroom
°F
°F
°F
°F
Common Ventilation Unit
Type .................................................... CW Ventilation Unit
Cooling Coil
Setpoint ..................................................................... 75.0 °F
Heating Coil
Setpoint ..................................................................... 70.0 °F
Fan Performance
Ventilation Fan Performance ..................................... 1.50 in wg
Exhaust Fan Performance ......................................... 1.00 in wg
Demand Controlled Ventilation
Used ........................................................................ Used
Base Ventilation Rate ................................................... 20
Min. CO2 Differential .................................................. 267
Max. CO2 Differential ................................................. 700
Outdoor Air CO2 Level ............................................... 393
Energy Simulation for Commercial Buildings
%
PPM
PPM
PPM
Page 48
2015 June 23
[ENERGY SIMULATION ]
Ventilation Reclaim
Type ........................ Energy Recovery Ventilator (ERV)
Efficiency ...................................................................... 65 %
Input Power .............................................................. 0.200 kW
Zone Configuration
No. of Floors .................................................................... 1
Use Typical Intermediate Floor? .................................. No
Configuration of Spaces and Zones
Building
Floor 1
D100 - Computer Server
D100 - Computer Server
D101 - Classroom
D101 - Classroom
D102 - Classroom
D102 - Classroom
D103 - Classroom
D103 - Classroom
D104 - Classroom
D104 - Classroom
D105 - South Vestibule
D105 - South Vestibule
D106 - Classroom
D106 - Classroom
D107 - Classroom
D107 - Classroom
D108 - Music Room
D108 - Music Room
D109 - Music Practice
D109 - Music Practice
D110 - Music Files
D110 - Music Files
D111 - Music Office
D111 - Music Office
D112 - West Vestibule
D112 - West Vestibule
D113 - Corridor
D113 - Corridor
D114 - Corridor
D114 – Corridor
Figure 3.3e - Equipment and System Wizard Data Summary
Open the air system and under the Vent System Components tab, Ventilation
Air, select ASHRAE 62.1-2007 as the Ventilation Sizing Method.
Next, calculate the air system by highlight the system on the list and select
reports/print view design reports.
HINT Select the Air System Sizing Summary report first to speed up the
terminal air system calculations. Refer to figure 3.4 below for details
Singapore Energy Simulation for Commercial Buildings
Page ‐ 49 -
2015 June 22
[ENERGY SIMULATION]
Figure 3.4 - Select Print View Design Reports
Figure 3.5 - Select Air System Sizing Summary Report
HINT: After the initial system calculations, choose to print view design results and select
all reports you want to view. Refer to the following reports for details of the design load
results for this air system.
Energy Simulation for Commercial Buildings
Page ‐ 50 -
2015 June 22
[ENERGY SIMULATION]
Section 2, Workshop 3
Results
Energy Simulation for Commercial Buildings
Page ‐ 51 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 52 -
2015 June 22
[ENERGY SIMULATION]
System Design Reports
Air System Information
Number of zones .......................................................... 15
Floor Area ............................................................ 9216.0 ft²
Location ..................................... Singapore, Singapore
2P FCU - Whole Building................................
Equipment Class .................................. TERM
Air System Type ................................... 2P-FC
Sizing Calculation Information
Zone and Space Sizing Method:
Zone CFM Sum of space airflow rates
Space CFM Individual peak space loads
Calculation Months .............................. Jan to Dec
Sizing Data .......................................... Calculated
Cooling Coil Sizing Data
Total coil load .................................... 2.1
Total coil load .......................................... 25.2
Sensible coil load .................................... 25.2
Coil CFM at Aug 1500 ............................ 2902
Max coil CFM ......................................... 2902
Sensible heat ratio ................................ 1.000
Water flow @ 10.0 °F rise ....................... 5.04
Tons
MBH
MBH
CFM
CFM
Load occurs at .................................................. Aug 1500
OA DB / WB ..................................................... 91.0 / 79.0 °F
Entering DB / WB ............................................ 82.0 / 71.0 °F
Leaving DB / WB ............................................. 74.0 / 68.6 °F
Bypass Factor .......................................................... 0.100
gpm
Ventilation Fan Sizing Data
Actual max CFM .................................... 2902 CFM
Standard CFM ........................................ 2897 CFM
Actual max CFM/ft² ................................. 0.31 CFM/ft²
Fan motor BHP .......................................................... 1.19 BHP
Fan motor kW ............................................................ 0.95 kW
Fan static ................................................................... 1.50 in wg
Exhaust Fan Sizing Data
Actual max CFM ..................................... 2902 CFM
Standard CFM ........................................ 2897 CFM
Actual max CFM/ft² ................................. 0.31 CFM/ft²
Fan motor BHP .......................................................... 0.79 BHP
Fan motor kW ............................................................ 0.63 kW
Fan static ................................................................... 1.00 in wg
Outdoor Ventilation Air Data
Design airflow CFM ............................... 2902 CFM
CFM/ft² .................................................... 0.31 CFM/ft²
CFM/person .................................... 12.84 CFM/Person
NOTE: This report is for the Dedicated Outdoor
Air System (DOAS) only. For Terminal Unit Sizing
data refer to the Zone Sizing Summary Report.
Energy Simulation for Commercial Buildings
Page 53
[ENERGY SIMULATION]
2015 April 02
Zone Sizing Summary
Air System Information
Air System Name ......... 2P FCU - Whole Building
Number of zones .......................................................... 15
Floor Area .............................................................. 9216.0 ft²
Location ....................................... Singapore, Singapore
Equipment Class ................................................ TERM
Air System Type ................................................. 2P-FC
Sizing Calculation Information
Zone and Space Sizing Method:
Zone CFM Sizing ................ Sum of space airflow rates
Space CFM Sizing ............ Individual peak space loads
Calculation Months ..................................... Jan to Dec
Sizing Data ................................................. Calculated
Terminal Unit Sizing Data - Cooling
Zone Name
D100 - IT Room
D101 - Classroom
D102 - Classroom
D103 - Classroom
D104 - Classroom
D105 - South Vestibule
D106 - Classroom
D107 - Classroom
D108 - Music Room
D109 - Music Practice
D110 - Music Files
D111 - Music Office
D112 - West Vestibule
D113 - Corridor
D114 - Corridor
Total
Coil
Load
(kBTUh)
5.9
28.5
28.5
28.5
32.1
2.7
31.0
29.5
60.5
2.7
2.2
4.8
2.8
10.1
12.3
Sens
Coil
Load
(kBTUh)
5.5
19.1
19.1
19.1
22.5
2.2
21.5
19.9
41.8
2.1
1.6
3.7
2.2
6.1
7.3
Coil
Entering
DB / WB
(°F)
76.4 / 64.3
76.1 / 66.7
76.1 / 66.7
76.1 / 66.7
76.1 / 66.4
76.6 / 65.6
76.3 / 66.7
76.2 / 66.8
76.2 / 66.4
76.3 / 66.1
76.5 / 66.3
76.5 / 65.8
76.6 / 65.6
76.6 / 67.9
76.6 / 68.0
Coil
Leaving
DB / WB
(°F)
58.7 / 57.6
58.2 / 57.3
58.2 / 57.3
58.2 / 57.3
58.5 / 57.6
58.6 / 57.6
58.8 / 57.9
58.5 / 57.7
58.0 / 57.1
59.0 / 58.1
58.6 / 57.7
58.8 / 57.8
58.8 / 57.8
58.0 / 57.3
58.0 / 57.3
Water
Flow
@ 10.0 °F
(gpm)
1.17
5.70
5.70
5.70
6.42
0.54
6.21
5.89
12.11
0.55
0.44
0.96
0.55
2.03
2.47
Time
of
Peak Coil
Load
Aug 1200
Jul 1500
Jul 1500
Jul 1500
Jul 1500
Aug 1500
Aug 1500
Aug 1500
Jul 1400
Jul 1500
Aug 1500
Aug 1500
Aug 1500
Aug 1200
Aug 1300
Zone
CFM/ft²
8.29
1.17
1.17
1.17
1.41
1.26
1.27
1.16
1.15
1.70
0.95
1.35
1.31
0.41
0.39
Terminal Unit Sizing Data - Heating, Fan, Ventilation
Zone Name
D100 - IT Room
D101 - Classroom
D102 - Classroom
D103 - Classroom
D104 - Classroom
D105 - South Vestibule
D106 - Classroom
D107 - Classroom
D108 - Music Room
D109 - Music Practice
D110 - Music Files
D111 - Music Office
D112 - West Vestibule
D113 - Corridor
D114 - Corridor
Heating
Coil
Load
(kBTUh)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Energy Simulation for Commercial Buildings
Heating
Coil
Ent/Lvg
DB
(°F)
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
-1.0 / -1.0
Htg Coil
Water
Flow
@20.0 °F
(gpm)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Fan
Design
Airflow
(CFM)
290
986
986
986
1184
111
1135
1040
2129
110
84
195
115
304
366
Fan
Motor
(BHP)
0.043
0.146
0.146
0.146
0.175
0.016
0.168
0.154
0.315
0.016
0.012
0.029
0.017
0.045
0.054
Fan
Motor
(kW)
0.034
0.116
0.116
0.116
0.139
0.013
0.133
0.122
0.250
0.013
0.010
0.023
0.013
0.036
0.043
OA Vent
Design
Airflow
(CFM)
7
351
351
351
351
5
358
358
611
24
11
19
5
45
57
Page 54
[ENERGY SIMULATION]
Zone Peak Sensible Loads
Zone
Cooling
Time of
Sensible
Peak Sensible
(kBTUh)
Cooling Load
5.3
Sep 1200
18.1
Aug 1500
18.1
Aug 1500
18.1
Aug 1500
21.7
Aug 1500
2.0
Aug 1500
20.8
Aug 1500
19.1
Aug 1500
39.0
Aug 1500
2.0
Aug 1500
1.5
Aug 1500
3.6
Aug 1500
2.1
Aug 1500
5.6
Aug 1400
6.7
Aug 1400
Zone Name
D100 - IT Room
D101 - Classroom
D102 - Classroom
D103 - Classroom
D104 - Classroom
D105 - South Vestibule
D106 - Classroom
D107 - Classroom
D108 - Music Room
D109 - Music Practice
D110 - Music Files
D111 - Music Office
D112 - West Vestibule
D113 - Corridor
D114 - Corridor
Zone
Heating
Load
(kBTUh)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Zone
Floor
Area
(ft²)
35.0
840.0
840.0
840.0
840.0
88.0
896.0
896.0
1856.0
65.0
88.0
144.0
88.0
750.0
950.0
Space Loads and Airflows
Zone Name /
Space Name
D100 - IT Room
D100 - IT Room
D101 - Classroom
D101 - Classroom
D102 - Classroom
D102 - Classroom
D103 - Classroom
D103 - Classroom
D104 - Classroom
D104 - Classroom
D105 - South Vestibule
D105 - South Vestibule
D106 - Classroom
D106 - Classroom
D107 - Classroom
D107 - Classroom
D108 - Music Room
D108 - Music Room
D109 - Music Practice
D109 - Music Practice
D110 - Music Files
D110 - Music Files
D111 - Music Office
D111 - Music Office
D112 - West Vestibule
D112 - West Vestibule
D113 - Corridor
D113 - Corridor
D114 - Corridor
D114 - Corridor
Mult.
Cooling
Sensible
(kBTUh)
Time
of
Load
Air
Flow
(CFM)
Heating
Load
(kBTUh)
Floor
Area
(ft²)
Space
CFM/ft²
1
5.3
Sep 1200
290
0.0
35.0
8.29
1
18.1
Aug 1500
986
0.0
840.0
1.17
1
18.1
Aug 1500
986
0.0
840.0
1.17
1
18.1
Aug 1500
986
0.0
840.0
1.17
1
21.7
Aug 1500
1184
0.0
840.0
1.41
1
2.0
Aug 1500
111
0.0
88.0
1.26
1
20.8
Aug 1500
1135
0.0
896.0
1.27
1
19.1
Aug 1500
1040
0.0
896.0
1.16
1
39.0
Aug 1500
2129
0.0
1856.0
1.15
1
2.0
Aug 1500
110
0.0
65.0
1.70
1
1.5
Aug 1500
84
0.0
88.0
0.95
1
3.6
Aug 1500
195
0.0
144.0
1.35
1
2.1
Aug 1500
115
0.0
88.0
1.31
1
5.6
Aug 1400
304
0.0
750.0
0.41
1
6.7
Aug 1400
366
0.0
950.0
0.39
Energy Simulation for Commercial Buildings
Page ‐ 55 -
[ENERGY SIMULATION]
2015 June 22
Ventilation Sizing Summary
1. Summary
Ventilation Sizing Method ........................................... ASHRAE Std 62.1-2007
Design Condition ................................................................. Cooling operation
Occupant Diversity .................................................................................... 1.000
Uncorrected Ventilation Airflow Rate ......................................................... 2902 CFM
System Ventilation Efficiency .................................................................... 1.000
Design Ventilation Airflow Rate ................................................................. 2902 CFM
2. Space Ventilation Analysis Table
Space
Floor
Zone Name / Space Name
D100 - Computer Server
D100 - IT Room
D101 - Classroom
D101 - Classroom
D102 - Classroom
D102 - Classroom
D103 - Classroom
D103 - Classroom
D104 - Classroom
D104 - Classroom
D105 - South Vestibule
D105 - South Vestibule
D106 - Classroom
D106 - Classroom
D107 - Classroom
D107 - Classroom
D108 - Music Room
D108 - Music Room
D109 - Music Practice
D109 - Music Practice
D110 - Music Files
D110 - Music Files
D111 - Music Office
D111 - Music Office
D112 - West Vestibule
D112 - West Vestibule
D113 - Corridor
D113 - Corridor
D114 - Corridor
D114 - Corridor
Totals (incl. Space
Multipliers)
Supply
Air (CFM)
Mult.
(Vpz)
Area (ft²)
(Az)
Area
Time
Outdoor
Averaged
Air Rate Occupancy
(CFM/ft²) (Occupants)
(Ra)
(Pz)
People
Outdoor
Air
Air Rate
Distribution
(CFM/person) Effectiveness
(Rp)
(Ez)
Space
Outdoor
Air (CFM)
(Voz)
Breathing
Zone
Space
Outdoor Air Ventilation
(CFM) Efficiency
(Vbz)
(Evz)
1
290
35.0
0.06
1.0
5.00
1.00
7
7
1.000
1
986
840.0
0.12
25.0
10.00
1.00
351
351
1.000
1
986
840.0
0.12
25.0
10.00
1.00
351
351
1.000
1
986
840.0
0.12
25.0
10.00
1.00
351
351
1.000
1
1184
840.0
0.12
25.0
10.00
1.00
351
351
1.000
1
111
88.0
0.06
2.0
0.00
1.00
5
5
1.000
1
1135
896.0
0.12
25.0
10.00
1.00
358
358
1.000
1
1040
896.0
0.12
25.0
10.00
1.00
358
358
1.000
1
2129
1856.0
0.06
50.0
10.00
1.00
611
611
1.000
1
110
65.0
0.06
2.0
10.00
1.00
24
24
1.000
1
84
88.0
0.12
1.0
0.00
1.00
11
11
1.000
1
195
144.0
0.06
2.0
5.00
1.00
19
19
1.000
1
115
88.0
0.06
2.0
0.00
1.00
5
5
1.000
1
304
750.0
0.06
8.0
0.00
1.00
45
45
1.000
1
366
950.0
0.06
8.0
0.00
1.00
57
57
1.000
2902
1.000
10023
Energy Simulation for Commercial Buildings
Page ‐ 56 -
[ENERGY SIMULATION]
2015 June 22
Air System Design Load Summary Report
ZONE LOADS
Window & Skylight Solar Loads
Wall Transmission
Roof Transmission
Window Transmission
Skylight Transmission
Door Loads
Floor Transmission
Partitions
Ceiling
Overhead Lighting
Task Lighting
Electric Equipment
People
Infiltration
Miscellaneous
Safety Factor
>> Total Zone Loads
Zone Conditioning
Plenum Wall Load
Plenum Roof Load
Plenum Lighting Load
Exhaust Fan Load
Ventilation Load
Ventilation Fan Load
Space Fan Coil Fans
Duct Heat Gain / Loss
>> Total System Loads
Cooling Coil
Heating Coil
Terminal Unit Cooling
Terminal Unit Heating
>> Total Conditioning
Key:
DESIGN COOLING
DESIGN HEATING
COOLING DATA AT Aug 1400
HEATING DATA AT DES HTG
COOLING OA DB / WB 90.7 °F / 78.9 °F
HEATING OA DB / WB 73.0 °F / 60.9 °F
Sensible
Latent
Sensible
Latent
Details
(BTU/hr)
(BTU/hr)
Details
(BTU/hr)
(BTU/hr)
768 ft²
9668
768 ft²
2400 ft²
4964
2400 ft²
0
9216 ft²
24140
9216 ft²
0
768 ft²
12543
768 ft²
0
0 ft²
0
0 ft²
0
0 ft²
0
0 ft²
0
9216 ft²
0
9216 ft²
0
0 ft²
0
0 ft²
0
0 ft²
0
0 ft²
0
16430 W
43721
0
0
7657 W
22639
0
0
4809 W
15015
0
0
225
36251
27000
0
0
0
10698
23224
0
0
0
0
0
0
0% / 0%
0
0
0%
0
0
179639
50224
0
0
189940
50224
0
0
0%
0
0
0
0%
0
0
0
0%
0
0
0
2902 CFM
2152
2902 CFM
-2152
2902 CFM
14933
37077
2902 CFM
-7234
0
2902 CFM
3227
2902 CFM
-3227
4012
-4012
0%
0
0%
0
214264
87301
-16626
0
24494
0
0
0
0
0
189771
86520
-16626
0
0
0
214264
86520
-16626
0
Positive values are clg loads
Positive values are htg loads
Negative values are htg loads
Negative values are clg loads
This report represents the “block load” of this system and includes the DOAS and
Terminal Units coil loads.
Energy Simulation for Commercial Buildings
Page ‐ 57 -
[ENERGY SIMULATION]
2015 June 22
Hourly Zone Load Report Example
Hour
0000
0100
0200
0300
0400
0500
0600
0700
0800
0900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
OA
TEMP
(°F)
81.7
81.2
80.6
80.2
79.8
79.7
79.9
80.5
81.5
83.0
84.7
86.6
88.4
89.8
90.7
91.0
90.7
89.9
88.6
87.2
85.7
84.4
83.3
82.4
ZONE
TEMP
(°F)
80.1
80.1
80.1
80.1
80.1
80.1
75.8
75.5
76.2
76.1
76.2
76.4
76.2
76.2
76.3
76.1
76.3
76.0
80.2
80.2
80.2
80.2
80.1
80.1
RH
(%)
58
59
60
61
61
62
75
75
64
61
60
59
58
57
56
56
64
68
55
55
56
56
57
58
ZONE
AIRFLOW
(CFM)
107.3
100.8
93.5
86.9
81.0
77.5
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
1183.9
161.0
154.4
141.7
132.3
122.7
114.2
ZONE: D104 - Classroom
DESIGN MONTH: JULY
ZONE
SENSIBLE
ZONE
LOAD
COND
(BTU/hr)
(BTU/hr)
6970.6
2558.6
6529.4
2402.7
6105.8
2229.6
5729.1
2069.9
5401.6
1929.9
5158.8
1845.1
5039.4
10398.3
5515.3
10441.6
14665.2
17540.9
16407.9
18938.8
17839.8
19844.5
19036.9
20206.2
19965.6
21428.0
20742.5
21957.1
21279.6
22114.9
21505.6
22477.8
15977.6
16423.3
13107.4
14003.5
11494.8
3852.1
10348.3
3692.1
9454.8
3387.1
8723.2
3160.2
8052.4
2929.8
7467.4
2726.0
TERMINAL
COOLING
COIL
(BTU/hr)
4191.0
3995.7
3775.0
3567.5
3381.9
3267.7
12470.4
15108.3
25315.2
27511.7
28436.8
28643.3
30655.6
31318.3
31386.5
32100.9
22208.7
17659.7
5735.1
5551.1
5196.3
4927.9
4645.2
4397.6
TERMINAL
HEATING
COIL
(BTU/hr)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
The Hourly Zone Load report displays zone temperatures and relative humidity values
along with zone sensible load and heat extraction rate.
Next, highlight the same air system and select Reports, Print/View Simulation Results
and View to generate the Air System Simulation Results.
Figure 3.6 - Select Simulation Results Reports
Energy Simulation for Commercial Buildings
Page ‐ 58 -
ZONE
HEATING
UNIT
(BTU/hr)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
2015 June 22
[ENERGY SIMULATION]
Figure 3.7 - Select Air System Simulation Results Reports
Figure 3.8 - Rerun and View all Air System Simulation Results
Energy Simulation for Commercial Buildings
Page ‐ 59 -
[ENERGY SIMULATION]
2015 June 22
System Simulation Reports Monthly, Daily and Hourly
Simulation Results
Monthly Air System Simulation Results
Air System Simulation Results (Table 1) :
Terminal
Cooling Coil
Load Ventilation Fan
(kBTU)
(kWh)
46860
244
Precool Coil
Load
(kBTU)
3660
Preheat Coil
Load
(kBTU)
0
February
3588
0
46287
March
3163
0
47470
Month
January
Vent. Reclaim
Device
(kWh)
Exhaust Fan
(kWh)
163
Terminal Fan
(kWh)
366
220
147
330
54
189
126
305
47
60
April
4420
0
56257
241
161
364
59
May
4015
0
57061
233
156
363
58
June
126
0
28105
10
7
106
6
July
4107
0
55443
251
168
378
61
August
3867
0
51874
233
156
359
58
September
2880
0
41439
178
119
283
44
October
4093
0
53064
244
163
369
61
November
2331
0
38676
168
112
270
42
89
0
15367
10
7
75
6
36339
0
537901
2222
1481
3567
557
December
Total
Air System Simulation Results (Table 2) :
Lighting
(kWh)
2834
Electric
Equipment
(kWh)
927
February
2571
840
March
2329
832
April
2811
911
May
2734
908
Month
January
June
591
490
July
2931
751
August
2734
908
September
2210
796
October
2834
927
November
2109
777
December
Total
611
506
27300
9575
Energy Simulation for Commercial Buildings
Page ‐ 60 -
[ENERGY SIMULATION]
Monthly Air System Simulation Graph
Precool Coil Load (kBTU)
Terminal Cooling Coil Load (kBTU)
55000
50000
45000
40000
kBTU
35000
30000
25000
20000
15000
10000
5000
0
Jan
Feb
Mar
Apr
Energy Simulation for Commercial Buildings
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Page ‐ 61 -
Dec
[ENERGY SIMULATION]
2015 June 22
Daily Air System Simulation Results
Daily Air System Simulation Results for August (Table 1):
Terminal
Precool Coil
Preheat Coil
Cooling Coil
Load
Load
Load Ventilation Fan
Day
(kBTU)
(kBTU)
(kBTU)
(kWh)
1
34
0
917
3
Exhaust Fan
(kWh)
2
Terminal Fan
(kWh)
10
2
0
0
545
0
0
2
3
123
0
2082
10
7
14
4
169
0
1988
10
7
14
5
200
0
2224
10
7
14
6
205
0
2315
10
7
14
7
197
0
2279
10
7
14
8
39
0
1130
3
2
10
9
0
0
531
0
0
1
10
183
0
2053
10
7
14
11
189
0
2181
10
7
14
12
190
0
2231
10
7
14
13
189
0
2141
10
7
14
14
153
0
1850
10
7
14
15
37
0
883
3
2
10
16
0
0
370
0
0
1
17
102
0
1755
10
7
14
18
184
0
1976
10
7
14
19
154
0
2093
10
7
14
20
184
0
2137
10
7
14
21
155
0
2127
10
7
14
22
35
0
877
3
2
10
23
0
0
691
0
0
2
24
123
0
2025
10
7
14
25
207
0
1937
10
7
14
26
187
0
2068
10
7
14
27
181
0
2117
10
7
14
28
209
0
2132
10
7
14
29
42
0
1143
3
2
10
30
0
0
655
0
0
2
31
198
0
2422
10
7
15
Total
3867
0
51874
233
156
359
Energy Simulation for Commercial Buildings
Page ‐ 62 -
[ENERGY SIMULATION]
2015 June 22
Daily Air System Simulation Results for August (Table 2):
Electric
Lighting
Equipment
Day
(kWh)
(kWh)
1
23
16
2
20
16
3
120
35
4
120
35
5
120
35
6
120
35
7
120
35
8
23
16
9
20
16
10
120
35
11
120
35
12
120
35
13
120
35
14
120
35
15
23
16
16
20
16
17
120
35
18
120
35
19
120
35
20
120
35
21
120
35
22
23
16
23
20
16
24
120
35
25
120
35
26
120
35
27
120
35
28
120
35
29
23
16
30
20
16
31
120
35
Total
2734
908
Energy Simulation for Commercial Buildings
Page ‐ 63 -
[ENERGY SIMULATION]
2015 June 22
Daily Air System Simulation Results
Daily Simulation Results for August
Precool Coil Load (kBTU)
Terminal Cooling Coil Load (kBTU)
2400
2200
2000
1800
kBTU
1600
1400
1200
1000
800
600
400
200
0
2
4
6
8
10
Energy Simulation for Commercial Buildings
12
14 16 18
Day of Month
20
22
24
26
28
Page ‐ 64 -
30
[ENERGY SIMULATION]
2015 June 22
Hourly Air System Simulation Results
Precool Coil Preheat Coil Terminal Cooling
Load
Load
Coil Load
Hour
(kBTU)
(kBTU)
(kBTU)
0000
0.0
0.0
2.0
Ventilation
Fan Exhaust Fan Terminal Fan
(kW)
(kW)
(kW)
0.0
0.0
0.0
Vent.
Reclaim
Device
(kW
0.0
0100
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0200
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0300
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0400
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0500
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0600
2.2
0.0
91.2
0.3
0.2
1.2
0.2
0700
8.9
0.0
98.2
0.9
0.6
1.2
0.2
0800
12.8
0.0
186.1
0.9
0.6
1.2
0.2
0900
14.5
0.0
197.0
0.9
0.6
1.2
0.2
1000
16.0
0.0
194.6
0.9
0.6
1.2
0.2
1100
18.9
0.0
204.7
0.9
0.6
1.2
0.2
1200
16.2
0.0
178.8
0.9
0.6
1.2
0.2
1300
18.5
0.0
209.7
0.9
0.6
1.2
0.2
1400
20.9
0.0
204.3
0.9
0.6
1.2
0.2
1500
22.3
0.0
197.3
0.9
0.6
1.2
0.2
1600
21.8
0.0
143.0
0.9
0.6
1.2
0.2
1700
13.6
0.0
115.5
0.7
0.4
1.2
0.2
1800
0.0
0.0
8.1
0.0
0.0
0.0
0.0
1900
0.0
0.0
7.4
0.0
0.0
0.0
0.0
2000
0.0
0.0
5.1
0.0
0.0
0.0
0.0
2100
0.0
0.0
4.1
0.0
0.0
0.0
0.0
2200
0.0
0.0
4.7
0.0
0.0
0.0
0.0
2300
0.0
0.0
5.8
0.0
0.0
0.0
0.0
Total
186.5
0.0
2067.6
10.4
7.0
14.3
2.4
Energy Simulation for Commercial Buildings
Page ‐ 65 -
[ENERGY SIMULATION]
2015 June 22
0000
Lighting
(kW)
0.8
Electric
Equipment
(kW)
0.7
0100
0.8
0.7
0200
0.8
0.7
0300
0.8
0.7
0400
0.8
0.7
0500
0.8
0.7
0600
0.8
0.7
Hour
0700
1.6
1.8
0800
16.7
3.8
0900
16.6
3.2
1000
16.6
3.2
1100
16.6
3.2
1200
10.9
3.8
1300
10.8
2.3
1400
7.5
1.4
1500
7.6
1.2
1600
2.7
1.8
1700
1.6
1.2
1800
0.8
0.7
1900
0.8
0.7
2000
0.8
0.7
2100
0.8
0.7
2200
0.8
0.7
2300
0.8
0.7
Total
119.9
35.5
Energy Simulation for Commercial Buildings
Page ‐ 66 -
[ENERGY SIMULATION]
Hourly Air System Simulation Results Graph
Hourly Simulation Results for Tuesday, August 26 (day 238) thru Thursday, August 28 (day 240)
Precool Coil Load (MBH)
Terminal Cooling Coil Load (MBH)
220
200
180
160
MBH
140
120
100
80
60
40
20
0
238
239
240
Day of Year
Energy Simulation for Commercial Buildings
Page ‐ 67 -
[ENERGY SIMULATION]
2015 June 22
Zone Temperature Report
1. Zone Temperature Statistics
Occ
Max
Zone
Temp
(°F)
77.1
Occ
Hours
More Than
5.0 °F
Above
Throt.
Range
0
Occ
Hours
1.0 to
5.0 °F
Above
Throt.
Range
0
Occ
Cooling
Setpoint
plus
Throt.
Range
(°F)
76.5
Occ
Hours
Within
Throt.
Range or
Deadband
2804
Occ
Heating
Setpoint
minus
Throt.
Range
(°F)
68.5
D101 - Classroom
76.5
0
0
76.5
2804
68.5
0
D102 - Classroom
76.5
0
0
76.5
2804
68.5
D103 - Classroom
76.5
0
0
76.5
2804
68.5
Zone Name
D100 - IT Room
Occ
Occ
Hours
Hours
1.0 to More Than
5.0 °F
5.0 °F
Below
Below
Throt.
Throt.
Range
Range
0
0
Occ
Unocc
Unocc
Heating
Setpoint
minus
Throt.
Range
(°F)
63.5
Unocc
Max
Zone
Temp
(°F)
80.4
Unocc
Cooling
Setpoint
plus
Throt.
Range
(°F)
81.5
Min
Zone
Temp
(°F)
74.8
0
75.1
80.3
81.5
63.5
77.1
0
0
0
75.1
80.3
81.5
63.5
77.1
0
75.1
80.3
81.5
63.5
77.1
Min
Zone
Temp
(°F)
80.3
D104 - Classroom
76.5
0
0
76.5
2804
68.5
0
0
75.0
80.4
81.5
63.5
77.1
D105 - South Vestibule
76.4
0
0
76.5
2804
68.5
0
0
75.0
80.4
81.5
63.5
75.9
D106 - Classroom
76.4
0
0
76.5
2804
68.5
0
0
75.0
80.4
81.5
63.5
76.9
D107 - Classroom
76.4
0
0
76.5
2804
68.5
0
0
75.1
80.3
81.5
63.5
77.1
D108 - Music Room
76.3
0
0
76.5
2804
68.5
0
0
75.1
80.2
81.5
63.5
77.4
D109 - Music Practice
76.6
0
0
76.5
2804
68.5
0
0
74.9
80.5
81.5
63.5
75.7
D110 - Music Files
76.5
0
0
76.5
2804
68.5
0
0
75.0
80.5
81.5
63.5
75.7
D111 - Music Office
76.5
0
0
76.5
2804
68.5
0
0
75.1
80.5
81.5
63.5
76.6
D112 - West Vestibule
76.4
0
0
76.5
2804
68.5
0
0
75.0
80.4
81.5
63.5
75.9
D113 - Corridor
76.4
0
0
76.5
2804
68.5
0
0
75.2
80.3
81.5
63.5
75.8
D114 - Corridor
76.4
0
0
76.5
2804
68.5
0
0
75.2
Note: For any occupied hours in which cooling is unavailable or scheduled off, zone temperature out of range statistics are not reported.
Note: For any occupied hours in which heating is unavailable or scheduled off, zone temperature out of range statistics are not reported.
80.3
81.5
63.5
75.8
Energy Simulation for Commercial Buildings
Page ‐ 68 -
[ENERGY SIMULATION]
2015 June 22
Section 3
Energy Simulation for Commercial Buildings
Page 69
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page 70
2015 June 22
[ENERGY SIMULATION]
Section 3_Workshop 4 - Modeling Chillers, Towers, Boilers and Hydronic Plants
This workshop consists of entering cooling and heating plant information including detailed
performance on chillers, towers, boilers and the distribution piping and pumping.
There are several ways to enter the data into HAP. One option is using the Equipment Wizard
found in HAP. Utilizing this wizard creates not only the Air Systems but also the hydronic plants
that connect to the air systems. When we used the Equipment Wizard to create the 4Pipe FCU
air system in workshop 3 the wizard automatically created the Chiller and Boiler plants for the air
system’s source of cooling and heating. Refer to Figures 3.3b and c for additional details. The
wizard created plants use the “auto-size” feature when creating the chillers and boilers. We now
create specific chillers, towers and boilers for our design alternatives.
The first step in this workshop is retrieving the second class archive which contains all air systems
for our design alternatives.
Retrieve Energy Simulation Archive 2 Unsolved
1. While in the existing project, go to the menu bar; select “Project \ Retrieve HAP v 4.9 Data.”
2. Navigate to folder 02 copied to the desktop and select Energy Simulation Unsolved Archives.
3. From this Folder - retrieve the archive “Singapore_HAP49_EnergySim Archive
2_Unsolved.E3A.” Allow this retrieval to “overwrite” the data created thus far in our workshops.
Be sure to click “Project, Save” to update your project files after retrieving this archive. The
project now contains all required air systems for the remaining workshops. Refer to Figure 4.1 for
details.
Figure 4.1 - Retrieve HAPv4.9 Energy Simulation Archive 2 Unsolved
Highlight and retrieve Energy Simulation Archive 2 Unsolved into the existing project and then
save the project.
In the previous workshop #3, we used the Equipment Wizard to create our air systems, chiller
plant and boiler plant for our 2 pipe fan coil air system with a DOAS for wing D of our building. In
Energy Simulation for Commercial Buildings
Page 71
2015 June 22
[ENERGY SIMULATION]
this workshop we create several chillers, a cooling tower and several SWH boilers for our building
air systems because the wizard created plants are sized only for the previously created 2-pipe fan
coil system for wing D.
HAP considers all the air systems assigned to the plant in determining the peak coincident, or
"block" load, taking into account diversity on several levels. Diversity is defined as the block load
divided by the sum of the individual peak loads.
HAP considers diversity between the zones within an air system and between systems when a
plant serves multiple air systems. The plant design load calculation analyses the total plant load
(sum of air system loads) for each hour and finds the largest load. This analysis includes the zone
and air system diversity. When using air system multipliers for identical air systems, the resulting
plant sizing includes those requirements in determining the peak plant load.
HAP calculates the total building, project or campus block load accounting for diversity in sizing
the plant and plant equipment.
We begin the process by determining the chiller and boiler plant sizing for the “A Base Case” and
“C Alt #2” design case. In the HAP main window, click on the Plant item in the tree and select
“create new plant” in the detail pane. Refer to Figure 4.2 for details.
Figure 4.2 - Create New Chiller Plant
This opens the Plant Input form for data entry. Please refer to Figure 4.3 for A Base Case Chilled
Water Plant sizing procedure.
Figure 4.3 - Generic Chiller Plant Sizing Details
Next click on the “Systems” tab and add the A Base Case air systems to the chilled water plant
and left click on the OK button. Refer to Figure 4.4 for details.
Energy Simulation for Commercial Buildings
Page 72
2015 June 22
[ENERGY SIMULATION]
Figure 4.4 - Add “A Base Case” Air Systems to the Generic Chilled Water Plant
This takes us back to the HAP plant screen showing the newly created plant on the list. Highlight
the plant and use the right mouse click then select “print/view design results” from the selection
list. Refer to Figures 4.5 and 4.6 for additional details.
Figure 4.5 - Calculate Chiller Plant Design Load
Energy Simulation for Commercial Buildings
Page 73
[ENERGY SIMULATION]
2015 June 22
Figure 4.6 - Select Print/View Design Results – Cooling Plant Sizing Summary
Review the follow details for the plant sizing.
Figure 4.7 - Chiller Plant Sizing Summary Report
1. Plant Information:
Plant Name ................................. A Base Case A/C CW Plant Sizing
Plant Type ........................................................ Generic Chilled Water
Design Weather ............................................... Singapore, Singapore
2. Cooling Plant Sizing Data:
Maximum Plant Load .....................................................................283.3 Tons
Load occurs at ...................................................................... Aug 1500
ft²/Ton ............................................................................................ 210.2 ft²/Ton
Floor area served by plant ........................................................ 59553.0 ft²
3. Coincident Air System Cooling Loads for Aug 1500
Air System Name
A01 - AHU A1 - Commons/Offices
A02 - AHU A2 - Classroom/Misc.
A03 - AHU B1 - Classrooms
A04 - Project 1 Gymnasium
A05 - AHU C2 - Aerobics Gym
A06 - AHU C3 - Locker Rooms
A07 - AHU C4 - Office/Classroom
A09 - Project 2 - Wing D PFPMXB
A10 - AHU D2 - Classrooms
Mult.
1
1
1
1
1
1
1
1
1
System
Cooling
Coil Load
( Tons )
47.5
43.7
50.6
49.0
13.2
26.2
12.6
20.0
20.6
System loads are for coils whose cooling source is ' Chilled Water ' or ' Any '.
Figure 4.7 details the chiller plant sizing summary for the A Base Design Case air systems.
The resulting peak plant load for the “A Base Case” is 283.3 tons (996.37kW). This peak
load includes diversity as previously discussed. For our “A Base Case” design we use two
(2) air-cooled chillers in our chiller plant.
Energy Simulation for Commercial Buildings
Page 74
[ENERGY SIMULATION]
2015 June 22
With the maximum plant load determined, we can select specific chillers for the chiller plant. This
is accomplished in one of several ways. For our exercise we selected the chiller in the e-Cat
Chiller Builder program. After finalizing the selection, we exported the chiller data for use in our
project. This allows us to import the actual chiller performance for a detailed energy analysis of
the chiller plant. Copies of the chiller data files are on the accompanying flash drive.
Air Cooled Chiller Selection
Design based on the following parameters.
Quantity:
2 Air-Cooled Packaged Scroll Chillers
Capacity:
150 Nominal Tons at 95º F (527.55kW @35⁰C)
LCHWT: 44º F (7⁰C)
ECHWT: 56º F (12⁰C)
Figure 4.8 - Details of Chiller Selection using e-Cat Selection Software.
Run the calculations and generate the Chiller Performance Report.
See following page for details.
Energy Simulation for Commercial Buildings
Page 75
[ENERGY SIMULATION]
2015 June 22
30RB with Greenspeed Technology
TM
Unit Information
Tag Name:........... A Base Case CH-1 and 2
Model Number: ......................... 30RB0522B
Quantity: ..................................................... 1
Manufacturing Source: ..... Shanghai, China
Refrigerant:........................................ R410A
Shipping Weight: .................................. 3296
Operating Weight: ................................ 3348
Unit Length: .......................................... 4798
Unit Width: ............................................ 2253
Unit Height:........................................... 2297
Evaporator Information
Fluid Type:............................... Fresh Water
Fouling Factor: .................................. 0.0180
Leaving Temperature: ............................. 7.0
Entering Temperature:........................... 12.0
Fluid Flow: ........................................... 25.57
Pressure Drop: ...................................... 91.6
kg
kg
mm
mm
mm
Performance Information
Cooling Capacity: ....................................... 536.5
Total Compressor Power: ........................... 165.7
Total Fan Motor Power: ................................ 13.0
Pump Power: ................................................ 9.53
Total Unit Power (without pump): ............... 178.7
Total Unit Power (with pump): .................... 188.2
Efficiency (without pump): ............................ 3.00
A-Weighted Sound Power Level: ..................... 94
A-Weighted Sound Pressure Level:................. 74
kW
kW
kW
kW
kW
kW
COP
dbA
dbA
Accessories and Installed Options
Opt. 254 Cu / Al Coil
(sqm-K)/kW
°C
°C
L/s
kPa
Condenser Information
Altitude: ...................................................... 0 m
Number of Fans: ......................................... 8
Total Condenser Fan Air Flow at 20°C:36107 L/s
Entering Air Temperature: ..................... 35.0 °C
Integrated Pump Information
Static Head at Pump:.................................. 275.1 kPa
Static Head External to Chiller: ................... 183.5 kPa
Electrical Information
Unit Voltage: .......................................... 380-3-50
Standby Power: ............................................ 10.4
Minimum Voltage: .......................................... 342
Maximum Voltage: ......................................... 418
Power Factor: ............................................... 0.85
Amps (Un)
Max Unit Current
Draw (RLA)
Max Start Up
Current (ICF)
Nominal Unit
Current Draw (A)
V-Ph-Hz
kW
Volts
Volts
Electrical
Circuit 1
415.0
Electrical
Circuit 2
---
629.0
---
327.0
---
All performance efficiency data are without pump.
Sound pressure level measured in accordance with JBT4330.
Sound pressure level is the data when the unit is placed in a free
field over a
reflecting plane.
Energy Simulation for Commercial Buildings
Page 76
[ENERGY SIMULATION]
Entering Chiller Performance Data
There are three (3) ways to enter chiller data into HAP.
1. Import Chiller
2. Chiller Template
3. User Defined Chiller Type
In this Workshop, we enter chiller data using method 1 and method 2.
For our Air Cooled Packaged Scroll Chillers we selected using the Packaged Chiller Builder
program, we exported the detailed chiller performance for use by HAP in simulating the hour-byhour operation of the chiller plant. To import the actual performance matrix of our chiller for use in
our plant model we use the “Import Chiller” utility in the chiller properties input form. Refer to
Figure 4.9a through Figure 4.9d for details.
We placed a Chiller Export Archive file on the accompanying Flash Drive. To Import this chiller for
this exercise open the chiller properties form and Double Click on the “New Default Chiller” in the
chiller Library, then click on the Import Chiller button as detailed in Figure 4.9a.
Figure 4.9a - Chiller Input Form – Import Chiller Data
Navigate to your desktop where we copied folder 02. Unsolved Workshop Archives and
select the “A Base Case CH-1 and 2.cd5.” Click the OPEN button to import the chiller into HAP.
Energy Simulation for Commercial Buildings
Page ‐ 77 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.9b – Chiller Properties General Tab – Imported Chiller Data
Note: The Chiller properties are imported from the archived file and include all selection design
inputs and calculated performances for IPLV and NPLV using the full operating matrix of the
chiller.
We can rename the default Chiller1 name to something that makes more sense i.e. “A Base Case
AC Chillers” or similar.
Energy Simulation for Commercial Buildings
Page ‐ 78 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.9c - Chiller Properties Design Inputs – Imported Chiller Data
Note: All data is part of the import file.
Energy Simulation for Commercial Buildings
Page ‐ 79 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.9d – Chiller Properties Performance Map – Imported Chiller Data
Using the Equipment Wizard in creating our C8 2-Pipe Fan Coil Unit air system in Workshop 3
also created a chiller and tower for this design alternative. Looking at the Chiller library we see
only one chiller on the list, the one from the wizard was deleted from the previous archive.
When using the Wizard in creating chillers the default sizing is “Auto-Sized” meaning the chiller
capacity defaults to the required capacity for the assigned air system coil loads. In order to
perform an accurate comparison of actual chiller performance we need to user define the
performance of this water-cooled screw chiller. We enter the chiller performance into HAP using
the “Chiller Template” utility in HAP.
Use the following information for modeling the water-cooled screw chiller for the C Alt 2 design.
Now calculate the design load for the “C” Alt-2 chiller plant.
Note: The calculated load for C Alt 2 is 225.0 tons [791.3 kW]. The chiller capacity and part load
performance used in the template input are detailed in Figures 4.10 through 4.11e, and resulted
from a preliminary selection from the e-Cat software and includes extra capacity.
Energy Simulation for Commercial Buildings
Page ‐ 80 -
[ENERGY SIMULATION]
2015 June 22
Integrated Part Load Value (AHRI)
IPLV:......................................................27.05 EER
Unit Performance
Percent Full Load Cooling Capacity, %
Percent of Full Load Power, %
Unloading Sequence
Cooling Capacity, Tons
Total Unit Power, kW
Efficiency, EER
Evaporator Data
Fluid Entering Temperature, °F
Fluid Leaving Temperature, °F
Fluid Flow Rate, gpm
Fouling Factor, (hr-sqft-F)/BTU
Condenser Data
Fluid Entering Temperature, °F
Fluid Leaving Temperature, °F
Fluid Flow Rate, gpm
Fouling Factor, (hr-sqft-F)/BTU
Figure 4.10 – Integrated Part Load Value
100
100.0
Default
274.0
162.6
20.23
75
61.6
Default
205.5
100.2
24.62
50
35.0
Default
137.0
56.8
28.93
25
17.4
Default
68.5
28.2
29.11
54.0
44.0
657.7
0.0001
51.5
44.0
657.7
0.0001
49.0
44.0
657.7
0.0001
46.5
44.0
657.7
0.0001
85.0
94.4
816.3
0.00025
75.0
81.9
816.3
0.00025
65.0
69.5
816.3
0.00025
65.0
67.2
816.3
0.00025
Certified in accordance with the AHRI Water-Cooled Water Chilling Packages Using Vapor Compression Cycle
Certification Program, which is based on AHRI Standard 550/590 (I-P). Certified units may be found in the AHRI
Directory at www.ahridirectory.org
Sound pressure level data used to develop this program was determined in accordance with AHRI Standard 575 for
water chillers in a free field and ANSI/AHRI Standard 370 for air cooled chillers.
Double click “New Default Chiller” and enter the IPLV data from Figure 4.10 as detailed in Figures 4.11a
through 4.11e.
Energy Simulation for Commercial Buildings
Page ‐ 81 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.11a – Define Chiller Part Load Performance
Figure 4.11b – Chiller Template Design Inputs
Energy Simulation for Commercial Buildings
Page ‐ 82 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.11c - Chiller Properties General Tab Template Data
Figure 4.11d - Chiller Properties Design Inputs Tab
Energy Simulation for Commercial Buildings
Page ‐ 83 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.11e – Chiller Properties Performance Map Tab
Note: The above inputs are IPLV rating points based on 44/56ºF LCHWT/ECHWT, with
adjusted Cooler and Condenser Water flow rates.
Energy Simulation for Commercial Buildings
Page ‐ 84 -
2015 June 22
[ENERGY SIMULATION]
Cooling Plant Sizing Summary Comparison Discussion
The maximum plant load for the water-cooled design case using air systems C1-C8 is 204 tons.
Note that some of these air systems are 4 pipe fan coil units.
For the air-cooled design case using air systems A01-A10, the plant load was 251.7 tons.
Some of these air systems are VAV. Both plants serve identical 59,553 ft² areas.
What contributes to the load difference between the plants?
We find the answer by comparing the Air System Design Load Summaries for the two plant
types. (Not done as part of this workshop).The air-cooled chiller plant requires more ventilation
air than the water-cooled chiller plant. But the primary reason for the tonnage difference is the 4
Pipe FCU system using DOAS only tempers the outside air to 72º F while the A01-10 VAV
systems temper the ventilation air to 55º F requiring an additional 47.7 tons of cooling.
Sum of ventilation air amounts for A01 - A10 = 32,299 cfm or 0.542 cfm/ft²
Sum of ventilation air amounts for C01 - C08 = 31,590 cfm or 0.530 cfm/ft²
We selected the ASHRAE 62.1-2007 Ventilation sizing for all air systems in both plants.
However, each VAV air system serves multiple zones requiring the use of the VRP and multiple
space equation for VAV systems in order to satisfy the critical zones requirements and comply
with ASHRAE 62.1-2007. The difference in the design cases results in a 47.7 ton
ventilation air load reduction.
Entering Cooling Tower Performance Data
Next, we need to verify the cooling tower performance for our water-cooled chiller. Before we
do, there are several important terms definitions related to cooling towers including:
1. Entering Wet Bulb temperature is an important parameter in tower selection. For most
areas in North America, an entering wet bulb temperature of 78°F [25.6ºC] is common.
2. Approach is the difference between the water leaving the tower and the entering wet
bulb temperature of the air. A 7°F [259.3º K] approach is common in HVAC systems with
a 78°F [25.6ºC] entering wet bulb and 85°F [29.4ºC] water leaving the tower. (85°F 78°F = 7°F) [29.4ºC – 25.6ºC = 259.3ºK]
3. Range is the difference in temperature of entering and leaving condenser water. An
approximate 10°F [260.9º K] range is most common in HVAC applications and reflects
approximately 3 gpm/ton flow rate in the condenser loop.
Check with your local cooling tower representative to confirm the design entering wet bulb and
approach values for your area. The tower range must match the chiller condenser ∆T.
1. Create a new cooling tower by opening the Cooling Tower Properties form.
2. Enter the cooling tower data found under the Chiller Properties Design Input Tab in
Figure 4.11 D.
3. See details in Figure 4.12.
Energy Simulation for Commercial Buildings
Page ‐ 85 -
2015 June 22
[ENERGY SIMULATION]
Figure 4.12 - Cooling Tower Properties for C Alt 2 WC Screw Chiller
1. Enter Cooling Tower Name
2. Select Cooling Tower radio button Modeling Method
3. Select gpm and enter the water flow rate matching the chiller properties
4. Enter Cooling Tower Model performance data
5. Select Fan Control type from dropdown and define fan performance
6. Click OK when finished
Energy Simulation for Commercial Buildings
Page ‐ 86 -
2015 June 22
[ENERGY SIMULATION]
Entering Boiler Performance Data
We are now ready to size our boiler plants and add boilers to our library. We start by sizing our
A Base Case boiler load as detailed in the following Figures 4.13a through 4.13d. Create a new
Generic Service Hot Water Plant and link all “A” designated air systems.
Figure 4.13a Generic Service Hot Water Plant
Figure 4.13b Link “A” Base Case Air Systems
Energy Simulation for Commercial Buildings
Page ‐ 87 -
[ENERGY SIMULATION]
2015 June 22
Figure 4.13c –Define Service Hot Water Consumption
Save plant inputs and generate plant sizing report as detailed below.
A Base Case SWH Plant
Plant Type Generic Service Hot Water
Design Weather
Singapore, Singapore
Heating Plant Sizing Data:
Maximum Plant Load
36.4
MBH
Maximum Pasteurization Load
25.3
Load occurs at
MBH
Jan 0900
Estimated Pasteurization Heater Capacity
Energy Simulation for Commercial Buildings
7.4
kW
Page ‐ 88 -
[ENERGY SIMULATION]
2015 June 22
Section 4
Energy Simulation for Commercial Buildings
Page ‐ 89 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 90 -
2015 June 22
[ENERGY SIMULATION]
Section 4 - Workshop 5 - Configuring Chiller Plants
We created two plants in our previous workshop, a chiller plant for our A Base Case and our C
Alt 2 Design, as displayed in Figure 5.1.
Figure 5.1 – Chiller Plants Created in WS4.
What is a Plant?
A Plant is the equipment and controls that provide cooling or heating to coils in one or more air
systems. Examples include chiller plants, hot water or steam boiler plants and remote source
chilled water, hot water or steam plants and service water heating plants. This workshop
consists of finalizing the two chiller plants created in Workshop 4.
The base design case chiller plant consists of two Carrier 30RBX150 A/C (air-cooled) packaged
scroll chillers. The air systems served by this plant include all “A” designated air systems with
chilled water coils. The pumping and piping distribution system is a primary only with variable
speed pumping and sized for a 12T [262ºK] with 2% piping heat gain factor.
The “C Alt 2” chiller plant serves the “C” designated air systems. This plant consists of one
222.5 ton Carrier 30XW water-cooled packaged screw chiller and a matching cooling tower. The
pumping and piping distribution system is a primary only variable speed system sized for a
12T and 2% piping heat gain factor.
For this workshop we can modify the previously created generic plants by changing the plant
type from “Generic” to Chiller Plant and complete the plant inputs for both plants as shown on
the following pages in Figures 5.2a through 5.2e.
Figure 5.2a – A Base Case Chiller Plant Data Inputs
Energy Simulation for Commercial Buildings
Page ‐ 91 -
2015 June 22
[ENERGY SIMULATION]
Figure 5.2b – A Base Case Air Systems
Figure 5.2c – Base Case Plant Configuration
Energy Simulation for Commercial Buildings
Page ‐ 92 -
2015 June 22
[ENERGY SIMULATION]
Figure 5.2d – Schedule of Equipment
Figure 5.2e – Configure Plant Distribution
Energy Simulation for Commercial Buildings
Page ‐ 93 -
[ENERGY SIMULATION]
2015 June 22
This completes the base case plant inputs please refer to the chiller plant input reports for C Alt
2 to configure the chiller plant. Use the same procedure for editing the plant described in the
base case above for the C Alt 2 plant. Refer to the following pages for the C Alt 2 plant details.
C Alt 2 Chiller Plant Input Data
1. General Details:
Plant Name ..................................... C Alt 2 W/C CW Plant Sizing(1)
Plant Type ...................................................................... Chiller Plant
2. Air Systems served by Plant:
Air System Name
C01 - 4PFCU D1 - Wing A (all)
C02 - 4PFCU D1 - Wing B (all)
C03 - AHU C1 - Gymnasium
C04 - AHU C2 - Aerobics Gym
C05 - AHU C3 - Locker Rooms
C06 - 4PFCU C4 - Office/Classrms
C08 - 4PFCU D1 - Wing D (all)
Mult.
1
1
1
1
1
1
1
3. Configuration
Equipment Sizing ........................................ User-Specified Capacities
Equipment
Quantity ............................................................................................ 1
Controls
Plant Control .......................................................... Equal Unloading
LCHWT Control ..................................................... Constant LCHWT
Design LCHWT ........................................................................... 44.0 °F
Features
Free Cooling ........................................................................ Not Used
Cooling Tower Configuration .............................................. Individual
4. Schedule of Equipment
Cooling Equipment
Sequence
CH-1
Name
Full Load
Capacity (Tons)
Cooler Flow
Rate
Condenser
Flow Rate
C Alt 2 W/C Chiller
274.0
657.6 gpm
822.0 gpm
Totals:
274.0
657.6 gpm
822.0 gpm
Cooling Tower Name
C Alt 2 Cooling Tower
822.0 gpm
822.0 gpm
5. Distribution
Chilled Water Distribution System
Type ................................................ Primary Only, Constant Speed
Cooling Coil Delta-T at Design .................................................... 12.0 °F
Pipe Heat Gain Factor ................................................................... 2.0 %
Energy Simulation for Commercial Buildings
Tower Flow
Rate
Page ‐ 94 -
[ENERGY SIMULATION]
2015 June 22
Fluid Properties
Fluid ............................................................................... Fresh Water
Density ........................................................................................ 62.4 lb/ft³
Specific Heat Capacity ................................................................ 1.00 BTU / (lb - °F)
Primary Loop
Pump for Eqpt.
CH-1
Flow Rate
Head
[ft wg]
657.6 gpm
70.0
Mechanical
Efficiency
(%)
70.0
Electrical
Efficiency
(%)
94.0
6. Condenser Water
Configuration
Pump Control .................................. Variable Flow / Variable Speed
Minimum Pump Flow ...................................................................... 80 %
Static Head .................................................................................. 10.0 ft wg
Pumps
Pump for Eqpt.
CH-1
Flow Rate
Head
[ft wg]
822.0 gpm
50.0
Mechanical
Efficiency
(%)
70.0
Electrical
Efficiency
(%)
94.0
D Alt3 SZCV/RTU
Next let’s look at how to configure a packaged roof top unit for energy simulation. Our “D”
Alternative consists of 36 single zone, constant air volume packaged rooftop air source heat
pump units. Open the Air System Properties form for [D31 – RTU D5 – Classroom D104] and
review the following details required for an energy.
Figure 5.3a – Packaged RTU-Configuration System Components –Supply Fan
Energy Simulation for Commercial Buildings
Page ‐ 95 -
2015 June 22
[ENERGY SIMULATION]
Figure 5.3b – Equipment – Central Cooling Unit
Configure the central cooling unit air cooled DX Equipment as follows:
1. The Design OAT populates to ARI Standard conditions. Enter the 95ºF [35ºC] design
conditions for St. Louis IAP, Missouri.
2. Equipment capacity defaults to auto-sized, however, we recommend entering actual
selected equipment manufacturer’s performance data by selecting “User-Defined
Capacity from Equipment Sizing dropdown.
3. Enter Gross Cooling Capacity from manufactures performance data
4. Select AHRI Performance Rating from dropdown and enter the SEER or EER efficiency
5. Select DX Configuration from dropdown
6. Enter Conventional Cutoff OAT
7. Uncheck Low Temperature Operation checkbox
8. Click OK to save
Next open the Central Heating Unit input form and enter the following information as detailed in
Figure 5.3c.
After entering the plant and equipment data, we can generate the Simulation Reports for each
of the four plants and packaged RTU. Please refer to the following pages for the detailed
simulation reports for “A” Base Case Chiller plant, Boiler plant and D31 – RTU D5 – Classroom
D104 rooftop unit.
Energy Simulation for Commercial Buildings
Page ‐ 96 -
[ENERGY SIMULATION]
2015 June 22
Section 4 Solutions
Energy Simulation for Commercial Buildings
Page ‐ 97 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 98 -
[ENERGY SIMULATION]
2015 June 22
Section 4_Workshop 5 Solutions
A Base Case Chiller Plant Simulation Results
Plant Simulation Results (Table 1) :
Cooling Coil
Load
Month
(kBTU)
January
809689
Plant Load
(kBTU)
829803
Chiller Output
(kBTU)
829803
Chiller Input
(kWh)
56318
Primary Chilled
Water Pump
(kWh)
2295
February
778796
798312
798312
55755
2171
March
756960
776350
776292
55159
2390
April
942290
966152
966152
70485
2522
May
950708
974822
974822
69825
2587
June
274919
282978
282978
20897
1983
July
647615
663746
663746
45599
2131
August
877203
899229
899229
62641
2430
September
672298
689520
689520
48117
2233
October
918126
941218
941218
66449
2491
November
637784
654141
654141
44515
2191
December
Total
1.0M
408971
419518
419518
23705
1979
8675357
8895788
8895731
619465
27403
Cooling Coil Load (kBTU)
Plant Cooling Load (kBTU)
Jan
May
Chiller Output (kBTU)
0.9M
0.8M
0.7M
kBTU
0.6M
0.5M
0.4M
0.3M
0.2M
0.1M
0.0
Feb
Mar
Apr
Energy Simulation for Commercial Buildings
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Page ‐ 99 -
[ENERGY SIMULATION]
2015 June 22
Daily Plant Simulation Results for August (Table 1) :
Cooling Coil
Load
Plant Load Chiller Output
Day
(kBTU)
(kBTU)
(kBTU)
1
28160
28860
28860
Chiller Input
(kWh)
1878
Primary Chilled
Water Pump
(kWh)
77
2
2860
2989
2989
230
63
3
35007
35875
35875
2387
83
4
35368
36245
36245
2514
84
5
36802
37722
37722
2739
87
6
38001
38956
38956
2867
90
7
36102
37000
37000
2648
85
8
26333
26979
26979
1756
73
9
2717
2843
2843
215
63
10
34559
35411
35411
2467
82
11
36885
37808
37808
2720
88
12
36186
37087
37087
2661
86
13
34472
35328
35328
2536
83
14
30813
31566
31566
2115
76
15
24930
25543
25543
1693
72
16
2530
2652
2652
201
63
17
29809
30533
30533
1936
74
18
34436
35285
35285
2462
81
19
33735
34571
34571
2400
82
20
36569
37484
37484
2674
87
21
35953
36844
36844
2517
84
22
24859
25467
25467
1588
71
23
3122
3256
3256
253
63
24
32591
33392
33392
2214
79
25
32360
33157
33157
2386
79
26
33968
34807
34807
2462
82
27
34097
34939
34939
2442
81
28
33922
34758
34758
2503
81
29
26336
26981
26981
1798
72
30
3003
3135
3135
249
63
31
40716
41754
41754
3131
98
Total
877203
899229
899229
62641
2430
Energy Simulation for Commercial Buildings
Page ‐ 100 -
[ENERGY SIMULATION]
2015 June 22
Daily Simulation Results for August
Cooling Coil Load (kBTU)
Plant Cooling Load (kBTU)
Chiller Output (kBTU)
0.040M
0.035M
0.030M
kBTU
0.025M
0.020M
0.015M
0.010M
0.005M
0.000
2
4
6
8
Energy Simulation for Commercial Buildings
10
12
14
16
18
Day of Month
20
22
24
26
28
30
Page ‐ 101 -
[ENERGY SIMULATION]
2015 June 22
Table 5.1 Hourly Plant Simulation Results for Tuesday, August 26
Cooling Coil
Load
Plant Load Chiller Output
Hour
(MBH)
(MBH)
(MBH)
0000
92.8
97.6
97.6
Chiller Input
(kW)
7.3
Primary Chilled
Water Pump
(kW)
2.6
0100
93.3
98.2
98.2
7.3
2.6
0200
93.7
98.6
98.6
7.3
2.6
0300
97.7
102.7
102.7
7.5
2.6
0400
96.9
101.8
101.8
7.5
2.6
0500
99.0
104.0
104.0
7.6
2.6
0600
1922.8
1967.2
1967.2
122.2
3.2
0700
1864.7
1907.6
1907.6
119.7
3.1
0800
2470.1
2529.3
2529.3
171.6
4.0
0900
2560.3
2622.2
2622.2
184.4
4.2
1000
2501.0
2561.1
2561.1
182.1
4.1
1100
2653.0
2717.5
2717.5
202.7
4.4
1200
2795.3
2864.1
2864.1
210.4
4.8
1300
2813.7
2883.0
2883.0
217.8
4.8
1400
2996.1
3071.2
3071.2
244.3
5.4
1500
2698.9
2764.8
2764.8
217.2
4.5
1600
2500.5
2560.6
2560.6
196.9
4.1
1700
2196.5
2248.1
2248.1
164.4
3.5
1800
845.0
864.9
864.9
42.4
2.6
1900
794.2
813.0
813.0
42.0
2.6
2000
805.6
824.6
824.6
41.5
2.6
2100
772.1
790.5
790.5
41.1
2.6
2200
103.6
108.7
108.7
8.3
2.6
2300
101.1
106.1
106.1
8.0
2.6
Total
33967.9
34807.4
34807.4
2461.6
81.5
Energy Simulation for Commercial Buildings
Page ‐ 102 -
[ENERGY SIMULATION]
2015 June 22
Table 6.1 Hourly Plant Simulation Results for Wednesday, August 27
Cooling Coil
Primary Chilled
Load
Plant Load Chiller Output
Chiller Input
Water Pump
Hour
(MBH)
(MBH)
(MBH)
(kW)
(kW)
0000
106.4
111.5
111.5
8.4
2.6
0100
107.9
113.1
113.1
8.5
2.6
0200
114.6
119.9
119.9
9.1
2.6
0300
107.6
112.7
112.7
8.4
2.6
0400
110.2
115.4
115.4
8.6
2.6
0500
108.6
113.7
113.7
8.5
2.6
0600
1891.1
1934.7
1934.7
122.6
3.1
0700
2056.8
2104.7
2104.7
133.1
3.3
0800
2676.8
2742.0
2742.0
189.4
4.5
0900
2873.3
2944.5
2944.5
218.2
5.0
1000
2938.1
3011.4
3011.4
223.9
5.2
1100
2935.2
3008.3
3008.3
224.3
5.2
1200
2517.3
2577.8
2577.8
190.2
4.1
1300
2523.3
2584.1
2584.1
194.6
4.1
1400
2467.3
2526.5
2526.5
187.4
4.0
1500
2477.4
2536.8
2536.8
187.1
4.0
1600
2345.1
2400.8
2400.8
172.9
3.8
1700
2251.0
2304.1
2304.1
162.7
3.6
1800
832.9
852.5
852.5
42.0
2.6
1900
823.8
843.3
843.3
41.9
2.6
2000
815.6
834.9
834.9
41.5
2.6
2100
806.6
825.7
825.7
41.5
2.6
2200
108.1
113.2
113.2
8.7
2.6
2300
102.5
107.6
107.6
8.1
2.6
Total
34097.4
34939.0
34939.0
2441.7
81.4
Energy Simulation for Commercial Buildings
Page ‐ 103 -
[ENERGY SIMULATION]
2015 June 22
Hourly Simulation Results for Tuesday, August 26 (day 238) thru Thursday, August 28 (day 240)
1. Unmet Load Statistics
Equipment
Capacity is
Sufficient
Month
(hrs)
January
744
Capacity
Insufficient
by 0%-5%
(hrs)
0
Capacity
Insufficient
by 5%-10%
(hrs)
0
Capacity
Insufficient
by >10%
(hrs)
0
Total Hours
with Unmet
Loads
0
Total Hours
with
Equipment
Loads
744
672
0
0
0
0
672
March
743
1
0
0
1
744
April
720
0
0
0
0
720
May
744
0
0
0
0
744
June
720
0
0
0
0
720
July
744
0
0
0
0
744
August
744
0
0
0
0
744
September
720
0
0
0
0
720
October
744
0
0
0
0
744
November
720
0
0
0
0
720
December
744
0
0
0
0
744
February
Total
8759
1
0
0
1
8760
Note: Data shown in this report is for diagnostic purposes only. Values represent total unmet hours for this plant. No deductions
are made when unmet hours for this plant coincide with those in another plant or system in the building.
Energy Simulation for Commercial Buildings
Page ‐ 104 -
[ENERGY SIMULATION]
2015 June 22
D Alt 3 Packaged RTU D-31 RTU D5 Classroom D104 Simulation Results
Air System Simulation Results (Table 1) :
Central
Central
Cooling Coil
Cooling Eqpt
Load
Load
Month
(kBTU)
(kBTU)
January
12
12
Central Unit
Clg Input
(kWh)
1
Supply Fan
(kWh)
343
Lighting
(kWh)
70
Electric
Equipment
(kWh)
143
February
31
31
2
323
66
119
March
69
69
5
285
59
78
April
1058
1058
80
356
72
64
May
1841
1841
130
300
62
43
June
4523
4523
345
171
41
35
July
3725
3725
315
50
16
16
August
8582
8582
641
358
73
62
September
4267
4267
315
356
72
48
October
809
809
60
314
65
55
November
251
251
18
298
62
88
December
Total
0
0
0
270
57
123
25168
25167
1911
3424
715
873
:
Energy Simulation for Commercial Buildings
Page ‐ 105 -
[ENERGY SIMULATION]
2015 June 22
Daily Air System Simulation Results for August (Table 1) :
Central
Central
Cooling Coil
Cooling Eqpt
Central Unit
Load
Load
Clg Input
Day
(kBTU)
(kBTU)
(kWh)
1
285
285
21
Supply Fan
(kWh)
1
Lighting
(kWh)
2
Electric
Equipment
(kWh)
1
2
53
53
4
0
2
1
3
476
476
34
2
11
2
4
470
470
35
2
11
2
5
513
513
39
2
11
2
6
528
528
40
3
11
2
7
509
509
39
3
11
2
8
290
290
22
1
2
1
9
39
39
3
0
2
1
10
488
488
37
3
11
2
11
510
510
38
2
11
2
12
508
508
38
2
11
2
13
492
492
37
2
11
2
14
423
423
32
2
11
2
15
273
273
21
1
2
1
16
20
20
2
0
2
1
17
408
408
29
2
11
2
18
468
468
36
2
11
2
19
474
474
35
2
11
2
20
501
501
37
2
11
2
21
493
493
36
2
11
2
22
253
253
19
1
2
1
23
83
83
7
0
2
1
24
455
455
33
2
11
2
25
456
456
36
2
11
2
26
472
472
36
2
11
2
27
478
478
36
2
11
2
28
481
481
38
3
11
2
29
297
297
23
1
2
1
30
90
90
8
0
2
1
31
579
579
43
3
11
2
Total
11865
11865
897
55
257
42
Energy Simulation for Commercial Buildings
Page ‐ 106 -
[ENERGY SIMULATION]
2015 June 22
0000
Central
Cooling Coil
Load
(MBH)
0.0
Central
Cooling Eqpt
Load
(MBH)
0.0
Central Unit
Clg Input
(kW)
0.0
Supply Fan
(kW)
0.0
Lighting
(kW)
0.1
Electric
Equipment
(kW)
0.0
0100
0.0
0.0
0.0
0.0
0.1
0.0
0200
0.0
0.0
0.0
0.0
0.1
0.0
0300
0.0
0.0
0.0
0.0
0.1
0.0
0400
0.0
0.0
0.0
0.0
0.1
0.0
Hour
0500
0.0
0.0
0.0
0.0
0.1
0.0
0600
25.5
25.5
1.7
0.2
0.1
0.0
0700
29.2
29.2
2.0
0.2
0.2
0.0
0800
40.3
40.3
2.8
0.2
1.6
0.3
0900
43.2
43.2
3.1
0.2
1.6
0.3
1000
47.5
47.5
3.5
0.2
1.6
0.3
1100
51.0
51.0
3.9
0.3
1.6
0.3
1200
45.0
45.0
3.5
0.2
0.9
0.3
1300
55.8
55.8
4.4
0.2
1.1
0.1
1400
57.8
57.8
4.7
0.2
0.8
0.0
1500
57.8
57.8
4.7
0.2
0.8
0.0
1600
50.2
50.2
4.1
0.2
0.3
0.0
1700
44.5
44.5
3.6
0.2
0.2
0.0
1800
0.0
0.0
0.0
0.0
0.1
0.0
1900
0.0
0.0
0.0
0.0
0.1
0.0
2000
0.0
0.0
0.0
0.0
0.1
0.0
2100
0.0
0.0
0.0
0.0
0.1
0.0
2200
0.0
0.0
0.0
0.0
0.1
0.0
2300
0.0
0.0
0.0
0.0
0.1
0.0
Total
547.8
547.8
42.2
2.2
11.4
1.7
Energy Simulation for Commercial Buildings
Page ‐ 107 -
[ENERGY SIMULATION]
2015 June 22
1. Unmet Load Statistics - Central Cooling Unit - Air-Cooled DX
Equipment
Capacity
Capacity
Capacity is
Insufficient
Insufficient
Sufficient
by 0%-5%
by 5%-10%
Month
(hrs)
(hrs)
(hrs)
January
338
0
0
February
Capacity
Insufficient
by >10%
(hrs)
0
Total Hours
with Unmet
Loads
0
Total Hours
with
Equipment
Loads
338
319
0
0
0
0
319
March
392
0
0
0
0
392
April
358
0
0
0
0
358
May
392
0
0
0
0
392
June
551
0
0
0
0
551
July
374
0
0
0
0
374
August
359
0
0
0
0
359
September
336
0
0
0
0
336
October
338
0
0
0
0
338
November
334
0
0
0
0
334
December
306
0
0
0
0
306
4397
0
0
0
0
4397
Total
1. Zone Temperature Statistics
Occ
Occ
Occ
Occ
Occ
Occ
Occ
Occ
Unocc
Unocc
Unocc
Heatin
Hours
Hours
g
Hours
More
Hours Cooling
Within Setpoi
Hours
More
Cooling
Heating
Than
1.0 to Setpoint
Throt.
nt
1.0 to
Than
Setpoint
Setpoint
Max
5.0 °F
5.0 °F
plus
Range minus
5.0 °F
5.0 °F
Min
Max
plus
minus
Zone
Above
Above
Throt.
or Throt.
Below
Below
Zone
Zone
Throt.
Throt.
Zone
Temp
Throt.
Throt.
Range
Dead- Range
Throt.
Throt.
Temp
Temp
Range
Range
Name
(°F)
Range
Range
(°F)
band
(°F)
Range
Range
(°F)
(°F)
(°F)
(°F)
Zone 1
74.0
0
0
74.0
2804
68.0
0
0
72.6
82.4
84.0
63.0
Note: For any occupied hours in which cooling is unavailable or scheduled off, zone temperature out of range statistics are not
reported.
Note: For any occupied hours in which heating is unavailable or scheduled off, zone temperature out of range statistics are not
reported.
Energy Simulation for Commercial Buildings
Occ
Page ‐ 108 -
Unocc
Min
Zone
Temp
(°F)
76.0
[ENERGY SIMULATION]
2015 June 22
Section 5 Inputs
Energy Simulation for Commercial Buildings
Page ‐ 109 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 110 -
2015 June 22
[ENERGY SIMULATION]
Section 5_Workshop 6 Defining and Simulating Buildings
Defining Buildings in HAP
The first step in this workshop is to retrieve Singapore_HAP49_EnergySim Archive
3_Unsolved into the project. However, before actually working with this archive, let us discuss
how HAP uses the term “building”.
A building in HAP is the “container” for all HVAC and non-HVAC systems for one design
scenario. Performing an energy analysis calculates annual energy costs for the building’s
energy consuming systems. System design load analysis in HAP, requires us to create
elements, spaces, zones, air systems, and plants like in the previous workshops, while a
"building" is only required for performing an energy simulation.
Taken literally, a building represents one structure. However, in HAP the definition of a building
is flexible. It can also represent a group of structures. For example, a "building" could represent
a campus in which all the structures are served by central steam and chilled water plant
equipment. Keep in mind, a design case can contain part of an actual building, a complete
building, or many buildings.
When using the Equipment Wizard HAP not only creates the Air Systems and Plants but also a
Building. The Wizard created Building includes the plants, air systems, spaces and all items
linked to the spaces like schedules, construction items etc.
One exercise included in this workshop is defining the Energy Charges by creating an Electric
Rate. There are several ways to create these energy rates including the Utility Rate Wizard,
importing previously created rates, use the state EIA average rates or user defining the rates.
For our workshop we create a complex electric rate that includes seasonal scheduling, time-ofday utility rate schedules and a demand clause. Create the Natural Gas utility rate as a simple
rate structure. Use the following values for creating the electric and fuel utility rates.
HTS Supplies
General Details
Rate Name ............................................ HTS Supplies
Rate Type ..................................................... Complex
Energy Units ......................................................... kWh
Conversion ...................................................... 1.00000
Demand Units ......................................................... kW
Customer Charge .................................................. 0.00
Minimum Charge ................................................... 0.00
Tax Rate ............................................................... 0.00
kWh/kWh
$
$
%
Time-Of-Day Scheduling
TOD Schedule Name ............................ HTS Supplies
Emissions Analysis
CO2e Factor ......................................................... 1.58 lb/kWh
Energy Charges
Type of Energy Charge ................................. Standard
Step Type
Season
Period
Block Size
Energy
All Seasons
Peak
9999999
Energy
All Seasons
Off-Peak
9999999
Energy Simulation for Commercial Buildings
Block Units
kWh
kWh
$/kWh
0.23670
0.14400
Page ‐ 111 -
[ENERGY SIMULATION]
2015 June 22
Demand Charges
Season
All Seasons
All Seasons
Period
Peak
Off-Peak
Block Size
9999999
9999999
Block Units
kW
kW
$/kW
7.49000
7.49000
Demand Clauses
No data specified.
This Concludes the Utility Rate Input
Energy Simulation for Commercial Buildings
Page ‐ 112 -
[ENERGY SIMULATION]
2015 June 22
Our next exercise in this workshop consists of creating the “Buildings” for this project. As
discussed in a previous paragraph, each “Building” represents a design alternative for
comparison of energy consumption etc. Our project includes the following four (4) designs:
I. Building Name:
A Base VAV-PFPMXB- ASHRAE 62.1-2007
Cooling Plant:
Air Systems:
Air System Types:
Ventilation Control:
Ventilation Sizing:
(2) 30RBA150 Air-Cooled Scroll Chiller
A01-A10
VAV PFPMXB, SZCV
Constant
ASHRAE 62.1-2007
II. Building Name:
Cooling Plant:
Air Systems:
Air System Types:
Ventilation Control:
Ventilation Sizing:
B Alt1 VAV-PFPMXB- ASHRAE 62.1-2007_DCV
(2) 30RBA150 Air-Cooled Scroll Chiller
B01-B10
VAV PFPMXB, SZCV
Demand Controlled Ventilation
ASHRAE 62.1-2007
III. Building Name:
Cooling Plant:
Air Systems:
Air System Types:
Ventilation Control:
Ventilation Sizing:
C Alt2-4PFCU-ASHRAE 62.1-2007_DOAS
(1) 30 XW09002P Water-Cooled Screw Chiller
C1-C8
2- Pipe Fan Coil Units, SZCV
Constant (dedicated outdoor air system for 2PFCU)
ASHRAE 62.1-2007
IV. Building Name:
Cooling Plant:
Air Systems:
Air System Types:
Ventilation Control:
Ventilation Sizing:
D Alt3 SZCV/RTU_ASHRAE 62.1-2007
None (Integral to RTU- Air Cooled DX)
D01-D36
SZCV RTU
Constant
ASHRAE 62.1-2007
Notice the “B Alt-1” scenario is a duplicate of the “A” Base Case except the associated air
systems use demand control ventilation to simulate ventilation loads. Using DCV is an energy
saving strategy that reduces ventilation air requirements resulting from diverse building
occupancy.
The “C Alt-2” design scenario uses a water cooled screw chiller to supply chilled water to 2-pipe
fan coil units and single zone air handlers. The fan coil systems utilize a common (dedicated)
ventilation air system resulting in a lower peak total ventilation airflow compared to the A and B
scenarios.
The “D-Alt 3” scenario uses multiple packaged single zone constant volume RTU units. The
rooftop units are self-contained DX cooling with air source heat pump heating and are not
connected to a chilled water or hot water plant.
In order to save time, the schedules and profiles applicable to the miscellaneous energy items
are completed as part of archive # 3.
Energy Simulation for Commercial Buildings
Page ‐ 113 -
2015 June 22
[ENERGY SIMULATION]
Figure 6.2 – Enter Building Data
Figure 6.3 – Assign Air Systems to Building Design
Energy Simulation for Commercial Buildings
Page ‐ 114 -
2015 June 22
[ENERGY SIMULATION]
Enter the following Miscellaneous Energy Users under the Misc. Energy Tab. Refer to Figure
6.4 for additional details. Note: the fractional schedules came as part of the archive, there is no
need to create the fractional schedules for this exercise
Name
Energy Type
Exterior Lighting
Electric
Kitchen Booster Heater
Electric
Aerobic Pool Heater
Electric
Aerobic Pool Circ. Pumps
Electric
Peak Use
20.5 kW
125 kW
175 kW
2.5 kW
Schedule
Parking Lot Lights
People-Classroom
Aerobic Pool Heater
Aerobic Pool Heater
Figure 6.4 – Misc. Energy Tab Input Details
Energy Simulation for Commercial Buildings
Page ‐ 115 -
2015 June 22
[ENERGY SIMULATION]
Figure 6.5 – Building Meters Tab
Highlight the “A Base Case Building” after saving it and then right mouse click and choose
Duplicate.
Rename the duplicate B Alt 1 VAV FPMXB DCV. Deselect the A Base Case plants and assign
the B Alt 1 plants to the B Alt 1 Building under the Plants Tab. Refer to Figure 6.6 for details.
Figure 6.6 – B Alt 1 Building Properties - Plants
Figure 6.7 – B Alt 1 Building Properties – Systems
These are the only required changes for the B Alt 1 Building design. Repeat the process for the
C Alt 2 design and D Alt 3 Design. After saving these additional buildings, highlight all four
design case buildings and perform the energy simulation.
Energy Simulation for Commercial Buildings
Page ‐ 116 -
[ENERGY SIMULATION]
2015 June 22
Section 5 Solutions
Energy Simulation for Commercial Buildings
Page ‐ 117 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 118 -
[ENERGY SIMULATION]
2015 June 22
Simulation Results
Table 1. Annual Costs
A Base VAVPFPMXBASHRAE 62.12007
(SGD)
60,636
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
(SGD)
60,195
Cooling
170,532
127,130
80,874
167,812
Heating
8,122
14,998
5,214
5,351
Pumps
7,705
7,457
39,826
310
0
0
19,662
0
246,996
209,780
184,888
235,797
45,052
44,799
44,143
45,328
Component
Air System Fans
Heat Rejection Fans
HVAC Sub-Total
Lights
Electric Equipment
Misc. Electric
C Alt 2 2P FCU
w/DOAS D Alt 3 PKG RTU
ASHRAE62.1ASHRAE62.12007
2007
(SGD)
(SGD)
39,312
62,323
20,114
19,993
19,709
20,251
182,934
181,756
179,306
184,244
Misc. Fuel Use
0
0
0
0
Non-HVAC Sub-Total
248,099
246,549
243,158
249,822
Grand Total
495,095
456,329
428,046
485,619
Table 2. Annual Cost per Unit Floor Area
A Base VAVPFPMXBASHRAE 62.12007
Component
(SGD/ft²)
Air System Fans
0.878
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
(SGD/ft²)
0.872
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
(SGD/ft²)
0.569
D Alt 3 PKG RTU
ASHRAE62.12007
(SGD/ft²)
0.903
Cooling
2.469
1.841
1.171
2.430
Heating
0.118
0.217
0.076
0.078
Pumps
0.112
0.108
0.577
0.005
Heat Rejection Fans
0.000
0.000
0.285
0.000
3.577
3.038
2.677
3.415
Lights
HVAC Sub-Total
0.652
0.649
0.639
0.656
Electric Equipment
0.291
0.290
0.285
0.293
Misc. Electric
2.649
2.632
2.597
2.668
Misc. Fuel Use
0.000
0.000
0.000
0.000
3.593
3.570
3.521
3.618
Non-HVAC Sub-Total
Grand Total
7.169
6.608
6.198
7.032
69057.0
69057.0
69057.0
69057.0
Conditioned Floor Area (ft²)
69057.0
69057.0
Note: Values in this table are calculated using the Gross Floor Area.
69057.0
69057.0
Gross Floor Area (ft²)
Energy Simulation for Commercial Buildings
Page ‐ 119 -
[ENERGY SIMULATION]
2015 June 22
Table 3. Component Cost as a Percentage of Total Cost
A Base VAVB Alt 1 VAVPFPMXBPFPMXBASHRAE 62.1ASHRAE 62.12007
2007 DCV
Component
(%)
(%)
Air System Fans
12.2
13.2
Cooling
34.4
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
(%)
9.2
D Alt 3 PKG RTU
ASHRAE62.12007
(%)
12.8
27.9
18.9
34.6
Heating
1.6
3.3
1.2
1.1
Pumps
1.6
1.6
9.3
0.1
Heat Rejection Fans
HVAC Sub-Total
0.0
0.0
4.6
0.0
49.9
46.0
43.2
48.6
Lights
9.1
9.8
10.3
9.3
Electric Equipment
4.1
4.4
4.6
4.2
36.9
39.8
41.9
37.9
0.0
0.0
0.0
0.0
Misc. Electric
Misc. Fuel Use
Non-HVAC Sub-Total
50.1
54.0
56.8
51.4
Grand Total
100.0
100.0
100.0
100.0
A Base VAVPFPMXBASHRAE 62.12007
(SGD)
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
(SGD)
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
(SGD)
D Alt 3 PKG RTU
ASHRAE62.12007
(SGD)
Annual Emissions Summary
Table 1. Annual Costs
Component
HVAC Components
Electric
246,991
209,776
184,886
235,807
Natural Gas
0
0
0
0
Fuel Oil
0
0
0
0
Propane
0
0
0
0
Remote HW
0
0
0
0
Remote Steam
0
0
0
0
Remote CW
0
0
0
0
246,991
209,776
184,886
235,807
248,105
246,554
243,157
249,817
Natural Gas
0
0
0
0
Fuel Oil
0
0
0
0
HVAC Sub-Total
Non-HVAC Components
Electric
Propane
0
0
0
0
Remote HW
0
0
0
0
Remote Steam
0
0
0
0
Non-HVAC Sub-Total
248,105
246,554
243,157
249,817
Grand Total
495,095
456,331
428,042
485,625
Energy Simulation for Commercial Buildings
Page ‐ 120 -
[ENERGY SIMULATION]
2015 June 22
Table 2. Annual Energy Consumption
A Base VAVPFPMXBASHRAE 62.1Component
2007
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
D Alt 3 PKG RTU
ASHRAE62.12007
902,991
771,644
689,880
857,339
Natural Gas (na)
0
0
0
0
Fuel Oil (na)
0
0
0
0
HVAC Components
Electric (kWh)
Propane (na)
0
0
0
0
Remote HW (na)
0
0
0
0
Remote Steam (na)
0
0
0
0
Remote CW (na)
0
0
0
0
Non-HVAC Components
Electric (kWh)
908,085
908,085
908,056
908,046
Natural Gas (na)
0
0
0
0
Fuel Oil (na)
0
0
0
0
Propane (na)
0
0
0
0
Remote HW (na)
0
0
0
0
Remote Steam (na)
0
0
0
0
Totals
Electric (kWh)
1,811,076
1,679,729
1,597,937
1,765,384
Natural Gas (na)
0
0
0
0
Fuel Oil (na)
0
0
0
0
Propane (na)
0
0
0
0
Remote HW (na)
0
0
0
0
Remote Steam (na)
0
0
0
0
Remote CW (na)
0
0
0
0
A Base VAVPFPMXBASHRAE 62.12007
2,852,450
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
2,645,571
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
2,516,779
D Alt 3 PKG RTU
ASHRAE62.12007
2,780,463
Table 3. Annual Emissions
Component
CO2 Equivalent (lb)
Energy Simulation for Commercial Buildings
Page ‐ 121 -
[ENERGY SIMULATION]
2015 June 22
Table 4. Annual Cost per Unit Floor Area
A Base VAVPFPMXBASHRAE 62.12007
Component
(SGD/ft²)
HVAC Components
Electric
3.577
B Alt 1 VAVPFPMXBASHRAE 62.12007 DCV
(SGD/ft²)
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
(SGD/ft²)
D Alt 3 PKG RTU
ASHRAE62.12007
(SGD/ft²)
3.038
2.677
3.415
Natural Gas
0.000
0.000
0.000
0.000
Fuel Oil
0.000
0.000
0.000
0.000
Propane
0.000
0.000
0.000
0.000
Remote HW
0.000
0.000
0.000
0.000
Remote Steam
0.000
0.000
0.000
0.000
Remote CW
0.000
0.000
0.000
0.000
3.577
3.038
2.677
3.415
Non-HVAC Components
Electric
3.593
3.570
3.521
3.618
Natural Gas
0.000
0.000
0.000
0.000
Fuel Oil
0.000
0.000
0.000
0.000
Propane
0.000
0.000
0.000
0.000
HVAC Sub-Total
Remote HW
0.000
0.000
0.000
0.000
Remote Steam
0.000
0.000
0.000
0.000
Non-HVAC Sub-Total
3.593
3.570
3.521
3.618
Grand Total
7.169
6.608
6.198
7.032
69057.0
69057.0
69057.0
69057.0
Conditioned Floor Area (ft²)
69057.0
69057.0
Note: Values in this table are calculated using the Gross Floor Area.
69057.0
69057.0
Gross Floor Area (ft²)
Energy Simulation for Commercial Buildings
Page ‐ 122 -
[ENERGY SIMULATION]
2015 June 22
Table 5. Component Cost as a Percentage of Total Cost
A Base VAVB Alt 1 VAVPFPMXBPFPMXBASHRAE 62.1ASHRAE 62.12007
2007 DCV
Component
(%)
(%)
HVAC Components
Electric
49.9
46.0
C Alt 2 2P FCU
w/DOAS
ASHRAE62.12007
(%)
D Alt 3 PKG RTU
ASHRAE62.12007
(%)
43.2
48.6
Natural Gas
0.0
0.0
0.0
0.0
Fuel Oil
0.0
0.0
0.0
0.0
Propane
0.0
0.0
0.0
0.0
Remote HW
0.0
0.0
0.0
0.0
Remote Steam
0.0
0.0
0.0
0.0
Remote CW
0.0
0.0
0.0
0.0
49.9
46.0
43.2
48.6
HVAC Sub-Total
Non-HVAC Components
Electric
50.1
54.0
56.8
51.4
Natural Gas
0.0
0.0
0.0
0.0
Fuel Oil
0.0
0.0
0.0
0.0
Propane
0.0
0.0
0.0
0.0
Remote HW
0.0
0.0
0.0
0.0
Remote Steam
0.0
0.0
0.0
0.0
Non-HVAC Sub-Total
50.1
54.0
56.8
51.4
Grand Total
100.0
100.0
100.0
100.0
Energy Simulation for Commercial Buildings
Page ‐ 123 -
[ENERGY SIMULATION]
2015 June 22
Annual Component Cost for C Alt 2
Air System Fans 9.2%
41.9% Misc. Electric
Cooling 18.9%
Heating 1.2%
Pumps 9.3%
Heat Rejection Fans 4.6%
4.6% Electric Equipment
Lights 10.3%
1. Annual Costs
Annual Cost
(SGD)
39,312
(SGD/ft²)
0.569
Percent of Total
(%)
9.2
Cooling
80,874
1.171
18.9
Heating
5,214
0.076
1.2
Component
Air System Fans
Pumps
39,826
0.577
9.3
Heat Rejection Fans
19,662
0.285
4.6
HVAC Sub-Total
Lights
Electric Equipment
184,888
2.677
43.2
44,143
0.639
10.3
19,709
0.285
4.6
179,306
2.597
41.9
0
0.000
0.0
243,158
3.521
56.8
Grand Total
428,046
6.198
Note: Cost per unit floor area is based on the gross building floor area.
100.0
Misc. Electric
Misc. Fuel Use
Non-HVAC Sub-Total
Gross Floor Area ....................................................... 69057.0 ft²
Conditioned Floor Area ............................................. 69057.0 ft²
Energy Simulation for Commercial Buildings
Page ‐ 124 -
[ENERGY SIMULATION]
2015 June 22
Annual Energy Cost
HVAC Electric 43.2%
56.8% Non-HVAC Electric
1. Annual Costs
Component
HVAC Components
Electric
Annual Cost
(SGD/yr)
(SGD/ft²)
Percent of Total
(%)
184,886
2.677
43.2
Natural Gas
0
0.000
0.0
Fuel Oil
0
0.000
0.0
Propane
0
0.000
0.0
Remote Hot Water
0
0.000
0.0
Remote Steam
0
0.000
0.0
Remote Chilled Water
0
0.000
0.0
184,886
2.677
43.2
56.8
HVAC Sub-Total
Non-HVAC Components
Electric
243,157
3.521
Natural Gas
0
0.000
0.0
Fuel Oil
0
0.000
0.0
Propane
0
0.000
0.0
Remote Hot Water
0
0.000
0.0
Remote Steam
0
0.000
0.0
Non-HVAC Sub-Total
243,157
3.521
56.8
Grand Total
428,042
6.198
100.0
Note: Cost per unit floor area is based on the gross building floor area.
Gross Floor Area ........................................ 69057.0 ft²
Conditioned Floor Area .............................. 69057.0 ft²
Energy Simulation for Commercial Buildings
Page ‐ 125 -
[ENERGY SIMULATION]
2015 June 22
Annual Cost HVAC and Non-HVAC
HVAC 43.2%
56.8% Non-HVAC
1. Annual Costs
Annual Cost
(SGD/yr)
184,888
(SGD/ft²)
2.677
243,158
3.521
56.8
Grand Total
428,046
6.198
Note: Cost per unit floor area is based on the gross building floor area.
100.0
Component
HVAC
Non-HVAC
Percent of Total
(%)
43.2
Gross Floor Area ....................................................... 69057.0 ft²
Conditioned Floor Area ............................................. 69057.0 ft²
Energy Simulation for Commercial Buildings
Page ‐ 126 -
[ENERGY SIMULATION]
2015 June 22
Energy Budget by System Component
1. Annual Coil Loads
Component
Cooling Coil Loads
Load
(kBTU)
6,222,422
(kBTU/ft²)
90.106
Heating Coil Loads
0
0.000
6,222,422
90.106
2. Energy Consumption by System Component
Site Energy
Component
(kBTU)
Air System Fans
501,117
Site Energy
(kBTU/ft²)
7.257
Source Energy
(kBTU)
1,789,704
Source Energy
(kBTU/ft²)
25.916
Grand Total
Cooling
1,029,636
14.910
3,677,270
53.250
Heating
66,415
0.962
237,197
3.435
Pumps
506,246
7.331
1,808,023
26.182
Cooling Towers
250,487
3.627
894,595
12.954
2,353,901
34.086
8,406,788
121.737
562,249
8.142
2,008,033
29.078
HVAC Sub-Total
Lights
Electric Equipment
Misc. Electric
250,835
3.632
895,839
12.973
2,285,228
33.092
8,161,527
118.185
Misc. Fuel Use
0
0.000
0
0.000
Non-HVAC Sub-Total
3,098,311
44.866
11,065,398
160.236
Grand Total
5,452,212
78.952
19,472,186
281.973
Notes:
1. 'Cooling Coil Loads' is the sum of all air system cooling coil loads.
2. 'Heating Coil Loads' is the sum of all air system heating coil loads.
3. Site Energy is the actual energy consumed.
4. Source Energy is the site energy divided by the electric generating efficiency (28.0%).
5. Source Energy for fuels equals the site energy value.
6. Energy per unit floor area is based on the gross building floor area.
Gross Floor Area ............................................ 69057.0 ft²
Conditioned Floor Area .................................. 69057.0 ft²
Energy Simulation for Commercial Buildings
Page ‐ 127 -
[ENERGY SIMULATION]
2015 June 22
Energy Budget by Energy Source
1. Annual Coil Loads
Component
Cooling Coil Loads
Load
(kBTU)
6,222,422
(kBTU/ft²)
90.106
Heating Coil Loads
0
0.000
6,222,422
90.106
2. Energy Consumption by Energy Source
Site Energy
Component
(kBTU)
Site Energy
(kBTU/ft²)
Source Energy
(kBTU)
Source Energy
(kBTU/ft²)
Grand Total
HVAC Components
Electric
2,353,870
34.086
8,406,680
121.735
Natural Gas
0
0.000
0
0.000
Fuel Oil
0
0.000
0
0.000
Propane
0
0.000
0
0.000
Remote Hot Water
0
0.000
0
0.000
Remote Steam
0
0.000
0
0.000
Remote Chilled Water
HVAC Sub-Total
Non-HVAC Components
Electric
0
0.000
0
0.000
2,353,870
34.086
8,406,680
121.735
3,098,289
44.866
11,065,315
160.235
Natural Gas
0
0.000
0
0.000
Fuel Oil
0
0.000
0
0.000
Propane
0
0.000
0
0.000
Remote Hot Water
0
0.000
0
0.000
Remote Steam
0
0.000
0
0.000
Non-HVAC Sub-Total
3,098,289
44.866
11,065,315
160.235
Grand Total
5,452,159
78.952
19,471,995
281.970
Notes:
1. 'Cooling Coil Loads' is the sum of all air system cooling coil loads.
2. 'Heating Coil Loads' is the sum of all air system heating coil loads.
3. Site Energy is the actual energy consumed.
4. Source Energy is the site energy divided by the electric generating efficiency (28.0%).
5. Source Energy for fuels equals the site energy value.
6. Energy per unit floor area is based on the gross building floor area.
Gross Floor Area ............................................ 69057.0 ft²
Conditioned Floor Area .................................. 69057.0 ft²
Energy Simulation for Commercial Buildings
Page ‐ 128 -
[ENERGY SIMULATION]
2015 June 22
Monthly Component Cost
Air System Fans
Cooling
Heating
Pumps
Heat Rejection Fans
Lights
Electric Equipment
Misc. Electric
18000
16000
Cost (SGD)
14000
12000
10000
8000
6000
4000
2000
0
Jan
Feb
Mar
1. HVAC Component Costs
Air System Fans
Month
(SGD)
January
4,194
Apr
May
Cooling
(SGD)
7,251
Jun
Jul
Month
Heating
(SGD)
548
Aug
Sep
Oct
Pumps
(SGD)
3,430
Nov
Dec
Heat Rejection Fans
(SGD)
1,834
HVAC Total
(SGD)
17,257
February
3,796
7,226
520
3,145
1,689
16,376
March
3,337
7,199
461
3,368
1,627
15,992
April
4,083
8,910
604
3,363
1,845
18,805
May
4,055
8,990
515
3,451
1,865
18,876
June
788
3,087
34
3,110
946
7,965
July
2,157
5,171
480
3,261
1,499
12,568
August
4,060
8,126
540
3,450
1,850
18,026
September
3,217
6,408
468
3,289
1,523
14,905
October
4,191
8,466
578
3,449
1,882
18,566
November
3,029
5,909
427
3,237
1,456
14,058
December
2,405
4,129
40
3,273
1,648
11,495
Total
39,312
2. Non-HVAC Component Costs
80,874
5,214
39,826
19,662
184,888
Electric
Equipment
(SGD)
1,938
Misc. Electric
(SGD)
17,740
Misc. Fuel Use
(SGD)
0
Lights
(SGD)
4,537
Month
January
Non-HVAC Total
(SGD)
24,215
Grand Total
(SGD)
41,472
February
4,162
1,780
16,316
0
22,259
38,635
March
3,775
1,693
15,308
0
20,776
36,768
April
4,496
1,916
16,841
0
23,254
42,059
May
4,399
1,894
16,364
0
22,656
41,532
June
1,142
822
7,502
0
9,465
17,430
July
3,863
1,665
9,800
0
15,329
27,897
August
4,408
1,897
16,269
0
22,575
40,601
September
3,658
1,648
14,172
0
19,478
34,383
42,003
October
4,533
1,936
16,967
0
23,437
November
3,467
1,581
14,278
0
19,326
33,384
December
1,702
938
17,748
0
20,388
31,883
44,143
19,709
179,306
0
243,158
428,046
Total
Energy Simulation for Commercial Buildings
Page ‐ 129 -
[ENERGY SIMULATION]
2015 June 22
Monthly Energy Cost by Energy Type
HVAC Electric
Non-HVAC Electric
24000
22000
Cost (SGD)
20000
18000
16000
14000
12000
10000
8000
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
1. HVAC Costs
Electric
(SGD)
17,256
Month
January
Natural Gas
(SGD)
0
Fuel Oil
(SGD)
0
Propane
(SGD)
0
Remote Hot
Remote Chilled
Water Remote Steam
Water
(SGD)
(SGD)
(SGD)
0
0
0
February
16,376
0
0
0
0
0
0
March
15,992
0
0
0
0
0
0
April
18,805
0
0
0
0
0
0
May
18,875
0
0
0
0
0
0
June
7,965
0
0
0
0
0
0
July
12,567
0
0
0
0
0
0
August
18,026
0
0
0
0
0
0
September
14,906
0
0
0
0
0
0
October
18,565
0
0
0
0
0
0
November
14,058
0
0
0
0
0
0
December
11,495
0
0
0
0
0
0
184,886
0
0
0
0
0
0
Month
January
Electric
(SGD)
24,214
Natural Gas
(SGD)
0
Fuel Oil
(SGD)
0
Propane
(SGD)
0
February
22,258
0
0
0
Total
2. Non-HVAC Costs
Remote Hot
Water Remote Steam
(SGD)
(SGD)
0
0
0
0
March
20,776
0
0
0
0
0
April
23,253
0
0
0
0
0
May
22,656
0
0
0
0
0
June
9,465
0
0
0
0
0
July
15,330
0
0
0
0
0
August
22,574
0
0
0
0
0
September
19,479
0
0
0
0
0
October
23,436
0
0
0
0
0
November
19,327
0
0
0
0
0
December
20,387
0
0
0
0
0
243,157
0
0
0
0
0
Total
Energy Simulation for Commercial Buildings
Page ‐ 130 -
[ENERGY SIMULATION]
Monthly Energy Use by System Component
1. Monthly Energy Use by System Component
Component
Jan
Air System Fans (kWh)
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
15795
14095
12394
15316
15205
2770
8172
15195
11713
15797
11118
9299
Cooling
27311
26832
26740
33423
33712
10852
19595
30410
23329
31913
21689
15963
Natural Gas (na)
Electric (kWh)
0
0
0
0
0
0
0
0
0
0
0
0
Fuel Oil (na)
0
0
0
0
0
0
0
0
0
0
0
0
Propane (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote HW (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote Steam (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote CW (na)
0
0
0
0
0
0
0
0
0
0
0
0
2063
1931
1713
2264
1931
120
1819
2021
1704
2178
1567
154
Natural Gas (na)
0
0
0
0
0
0
0
0
0
0
0
0
Fuel Oil (na)
0
0
0
0
0
0
0
0
0
0
0
0
Heating
Electric (kWh)
Propane (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote HW (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote Steam (na)
0
0
0
0
0
0
0
0
0
0
0
0
12919
11678
12509
12615
12940
10931
12356
12913
11975
13002
11882
12653
6906
6271
6044
6921
6992
3327
5678
6922
5543
7094
5342
6373
Pumps (kWh)
Clg. Tower Fans (kWh)
Lighting (kWh)
17087
15455
14023
16866
16495
4014
14640
16495
13317
17087
12726
6582
Electric Eqpt. (kWh)
7299
6609
6290
7189
7101
2890
6310
7101
6000
7299
5802
3625
Misc. Electric (kWh)
66818
60584
56856
63174
61362
26370
37136
60885
51594
63958
52406
68620
0
0
0
0
0
0
0
0
0
0
0
0
Misc. Fuel
Natural Gas (na)
Propane (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote HW (na)
0
0
0
0
0
0
0
0
0
0
0
0
Remote Steam (na)
0
0
0
0
0
0
0
0
0
0
0
0
Energy Simulation for Commercial Buildings
Page ‐ 131 -
[ENERGY SIMULATION]
Monthly Energy Use by Energy Type
1. HVAC Energy Use
Electric
Month
(kWh)
Jan
64,993
Natural Gas
(na)
0
Fuel Oil
(na)
0
Propane
(na)
0
Remote HW
(na)
0
Remote Steam
(na)
0
Remote CW
(na)
0
0
0
0
0
0
0
Feb
60,806
Mar
59,399
0
0
0
0
0
0
Apr
70,539
0
0
0
0
0
0
May
70,781
0
0
0
0
0
0
Jun
28,000
0
0
0
0
0
0
Jul
47,619
0
0
0
0
0
0
Aug
67,458
0
0
0
0
0
0
Sep
54,264
0
0
0
0
0
0
Oct
69,982
0
0
0
0
0
0
Nov
51,597
0
0
0
0
0
0
Dec
44,442
0
0
0
0
0
0
689,880
0
0
0
0
0
0
Totals
2. Non-HVAC Energy Use
Electric
Month
(kWh)
Jan
91,201
Natural Gas
(na)
0
Fuel Oil
(na)
0
Propane
(na)
0
Remote HW
(na)
0
Remote Steam
(na)
0
0
0
0
0
0
Feb
82,647
Mar
77,165
0
0
0
0
0
Apr
87,227
0
0
0
0
0
May
84,957
0
0
0
0
0
Jun
33,273
0
0
0
0
0
Jul
58,092
0
0
0
0
0
Aug
84,480
0
0
0
0
0
Sep
70,914
0
0
0
0
0
Oct
88,342
0
0
0
0
0
Nov
70,936
0
0
0
0
0
Dec
78,821
0
0
0
0
0
908,056
0
0
0
0
0
Totals
Energy Simulation for Commercial Buildings
Page ‐ 132 -
[ENERGY SIMULATION]
2015 June 22
Electric Billing Details
1. Component Charges
Billing
Period
Jan
Energy Charges Demand Charges
(SGD)
(SGD)
35,228
6,243
Customer
Charges
(SGD)
0
Taxes
(SGD)
0
Total Charge
(SGD)
41,471
0
0
38,635
Feb
32,376
6,259
Mar
30,600
6,169
0
0
36,769
Apr
35,694
6,364
0
0
42,058
May
35,166
6,365
0
0
41,531
Jun
12,909
4,521
0
0
17,431
Jul
23,457
4,439
0
0
27,896
Aug
34,344
6,257
0
0
40,601
Sep
28,034
6,350
0
0
34,384
Oct
35,782
6,220
0
0
42,002
Nov
27,354
6,030
0
0
33,384
Dec
27,596
4,287
0
0
31,883
358,543
69,504
0
0
428,047
Totals
2. Totals
Billing
Period
Jan
Total Charges
(SGD)
41,471
Total
Consumption
(kWh)
156,198
Avg Price
(SGD/kWh)
0.2655
Feb
38,635
143,455
0.2693
Mar
36,769
136,569
0.2692
Apr
42,058
157,768
0.2666
May
41,531
155,738
0.2667
Jun
17,431
61,273
0.2845
Jul
27,896
105,708
0.2639
Aug
40,601
151,942
0.2672
Sep
34,384
125,176
0.2747
Oct
42,002
158,327
0.2653
Nov
33,384
122,532
0.2725
31,883
123,269
0.2586
428,047
1,597,955
0.2679
Dec
Totals
Energy Simulation for Commercial Buildings
Page ‐ 133 -
[ENERGY SIMULATION]
2015 June 22
3. Consumption Totals
Billing
Peak
Period
(kWh)
Jan
137,385
Mid-Peak
(kWh)
0
Normal Peak
(kWh)
0
Off-Peak
(kWh)
18,813
Overall
(kWh)
156,198
143,455
Feb
126,416
0
0
17,039
Mar
117,954
0
0
18,614
136,569
Apr
139,978
0
0
17,790
157,768
May
137,427
0
0
18,311
155,738
Jun
44,078
0
0
17,195
61,273
Jul
88,833
0
0
16,875
105,708
Aug
134,462
0
0
17,480
151,942
Sep
107,972
0
0
17,204
125,176
Oct
140,057
0
0
18,270
158,327
Nov
104,744
0
0
17,789
122,532
Dec
106,210
0
0
17,059
123,269
1,385,517
0
0
212,438
1,597,955
Totals
4. Billing Demands
Billing
Period
Jan
Peak
(kW)
623.4
Mid-Peak
(kW)
0.0
Normal Peak
(kW)
0.0
Off-Peak
(kW)
210.1
Overall
(kW)
623.4
Feb
628.0
0.0
0.0
207.6
628.0
Mar
617.4
0.0
0.0
206.2
617.4
Apr
644.5
0.0
0.0
205.2
644.5
May
642.0
0.0
0.0
207.9
642.0
Jun
400.3
0.0
0.0
203.4
400.3
Jul
403.9
0.0
0.0
188.8
403.9
Aug
638.5
0.0
0.0
196.9
638.5
Sep
639.4
0.0
0.0
208.4
639.4
Oct
634.2
0.0
0.0
196.2
634.2
Nov
613.5
0.0
0.0
191.6
613.5
Dec
393.8
0.0
0.0
178.6
393.8
5. Maximum Demands
Billing
Period
Jan
Peak
(kW)
623.4
Mid-Peak
(kW)
0.0
Normal Peak
(kW)
0.0
Off-Peak
(kW)
210.1
Overall
(kW)
623.4
Feb
628.0
0.0
0.0
207.6
628.0
Mar
617.4
0.0
0.0
206.2
617.4
Apr
644.5
0.0
0.0
205.2
644.5
May
642.0
0.0
0.0
207.9
642.0
Jun
400.3
0.0
0.0
203.4
400.3
Jul
403.9
0.0
0.0
188.8
403.9
Aug
638.5
0.0
0.0
196.9
638.5
Sep
639.4
0.0
0.0
208.4
639.4
Oct
634.2
0.0
0.0
196.2
634.2
Nov
613.5
0.0
0.0
191.6
613.5
Dec
393.8
0.0
0.0
178.6
393.8
Energy Simulation for Commercial Buildings
Page ‐ 134 -
[ENERGY SIMULATION]
2015 June 22
6. Time of Maximum Demands
Billing
Peak
Period
(m/d/h)
Jan
1/26/0900
Mid-Peak
(m/d/h)
n/a
Normal Peak
(m/d/h)
n/a
Off-Peak
(m/d/h)
1/26/0600
Overall
(m/d/h)
1/26/0900
Feb
2/2/0900
n/a
n/a
2/2/0600
2/2/0900
Mar
3/30/0900
n/a
n/a
3/23/0600
3/30/0900
Apr
4/27/0900
n/a
n/a
4/20/0600
4/27/0900
May
5/18/0900
n/a
n/a
5/25/0600
5/18/0900
Jun
6/29/0800
n/a
n/a
6/4/0000
6/29/0800
Jul
7/20/1100
n/a
n/a
7/23/0000
7/20/1100
Aug
8/31/0900
n/a
n/a
8/31/0600
8/31/0900
Sep
9/14/0900
n/a
n/a
9/14/0600
9/14/0900
Oct
10/26/0900
n/a
n/a
10/26/0600
10/26/0900
Nov
11/2/0900
n/a
n/a
11/26/0000
11/2/0900
Dec
12/1/0800
n/a
n/a
12/3/0000
12/1/0800
Hourly Energy Use Profile
Hour
0000
0100
0200
0300
0400
0500
0600
0700
0800
0900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
Wednesday
Aug 26
(kW)
58.1
58.1
58.1
58.1
47.9
37.7
158.9
338.0
592.3
562.7
541.9
561.1
500.2
470.5
422.4
437.2
369.5
178.7
133.6
130.4
131.5
139.1
64.0
58.1
Thursday
Aug 27
(kW)
173.6
58.2
58.2
58.3
48.0
37.8
157.4
348.4
590.5
594.8
581.2
563.4
491.5
473.3
412.7
412.3
366.9
181.9
135.9
135.9
134.3
144.3
64.0
58.1
Friday
Aug 28
(kW)
58.2
58.2
58.2
58.2
48.0
37.8
170.4
353.8
570.3
563.7
547.4
531.0
485.1
456.4
404.6
406.9
362.4
172.8
129.1
127.3
128.6
140.4
64.2
58.3
Energy Simulation for Commercial Buildings
Page ‐ 135 -
[ENERGY SIMULATION]
Hourly Energy Use Graph
Electric Use Profiles - Tuesday, August 26 (day 238) thru Thursday, August 28 (day 240)
600
550
500
450
Usage ( kW )
400
350
300
250
200
150
100
50
0
238
239
240
Day of Year
Energy Simulation for Commercial Buildings
Page ‐ 136 -
[ENERGY SIMULATION]
Appendix “A”
Energy Simulation for Commercial Buildings
Page ‐ 137 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 138 -
2015 June 22
[ENERGY SIMULATION]
Appendix “A” Air System Schematics
Energy Simulation for Commercial Buildings
Page ‐ 139 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 140 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 141 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 142 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 143 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 144 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 145 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 146 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 147 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 148 -
2015 June 22
Energy Simulation for Commercial Buildings
[ENERGY SIMULATION]
Page ‐ 149 -
2015 June 22
[ENERGY SIMULATION]
Induction Beam System Schematic
Energy Simulation for Commercial Buildings
Page ‐ 150 -
2015 June 22
[ENERGY SIMULATION]
Induction Beam Terminal Diagram
Chilled Beam System Schematic
Chilled Beam Terminal Diagram
Energy Simulation for Commercial Buildings
Page ‐ 151 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 152 -
[ENERGY SIMULATION]
2015 June 22
Appendix”B”
APPENDIX B
Application Topics
Energy Simulation for Commercial Buildings
Page ‐ 153 -
2015 June 22
[ENERGY SIMULATION]
Blank Page
Energy Simulation for Commercial Buildings
Page ‐ 154 -
[ENERGY SIMULATION]
2015 June 22
Putting Load Calculation Methods in Perspective
By Rudy Romijn, Regional Sales Manager, Carrier Software Systems
Over the years our industry has used many methods for performing cooling load calculations.
Comparing these methods provides a useful perspective on the benefits of the methods currently
employed by engineers, and ultimately helps in understanding output data provided by
engineering software like HAP.
Those of us who started in this business before the age of computers can appreciate Figure 1
shown below. It illustrates the relationship between complexity and accuracy that many of us had
to grapple with for five of the principal load methods used over the years.
Load Estima ting M eth ods
AS HRAE Heat
Balance Method
A
C
C
U
R
A
C
Y
ASHRAE RTS
ASHRAE Transf er Functions
ASHRAE CLTD/CLF
Carrier E20 M ethod
Instantaneous Q=U A TD
INC RE AS IN G C OM P LE X IT Y
Figure B-1. Load Estimating Methodologies
In the past, we calculated loads by hand using the “instantaneous method” which assumed heat
gains were instantly converted to cooling loads. This method was simple and fast, but was
unreliable because it ignored processes such as heat storage and radiation transfer, which affect
the rate at which heat gains become cooling loads.
In 1960, Carrier published its System Design Manual, which included tables of Equivalent
Temperature Differences (ETD) and Storage Load Factors (SLF) to predict cooling loads, which
incorporated the effects of heat storage by building materials, and the effects of building
orientation and occupancy cycle. Later, in the 1970s ASHRAE published its CLTD/CLF method,
which incorporated the same kind of considerations. As hand calculation procedures, both
methods did a good job of balancing complexity (and therefore effort) with accuracy. However,
both methods lacked flexibility. Building loads are affected by a wide variety of factors involving
design, construction, environment and building use. Table-based hand calculation methods
typically dealt with a fixed set of basic conditions (such as envelope loads for July 16:00, 40
degrees north latitude) and then attempted to handle other conditions via correction factors.
Ultimately, this approach introduced errors and reduced accuracy when compared with methods
that are more complex. We needed a way of calculating loads specific to each design
application.
Energy Simulation for Commercial Buildings
Page ‐ 155 -
2015 June 22
[ENERGY SIMULATION]
The Heat Balance Method, the most rigorous method of calculating building loads, provides one
solution to this problem. Heat balance is actually the foundation of all the other methods of
calculating building loads. The heat balance method evaluates each conductive, convective,
radiative and heat storage process that occurs in the building using the fundamental laws of heat
transfer and thermodynamics. Using the heat balance method to determine building heat transfer
requires an equation written for each surface and mass element considering each process
involved. By solving all heat balances equations simultaneously, the total rate of heat
transferred to room air can be determined and the dynamic ebb and flow of heat in the room can
be successfully evaluated. The Heat Balance method can be highly accurate but it is also
complex and requires powerful computer hardware, detailed inputs and long calculation time.
An alternate solution is the ASHRAE endorsed Transfer Function Method of calculating loads,
and which is used in the HAP, System Design Load, Block Load and Block Load Lite programs
produced by Carrier. The Transfer Function Method uses some mathematical “tricks” to simplify
the heat balance solution process, thereby yielding calculation times that are faster than those of
the Heat Balance Method without sacrificing too much of its accuracy. The Transfer Function
procedure calculates how heat gains from sources such as warm ambient air, solar radiation,
lights, people, etc. are converted to cooling loads via conduction, convection, radiation and heat
storage processes. The procedures therefore account for the dynamic heat transfer found in a
“real world” building. Further, calculations account for specific design, construction,
environmental and building usage conditions and are therefore customized to each building
application. Thus, for the current state of technology of computerized engineering tools, Transfer
Functions provide a good compromise between complexity and accuracy.
Figure B-2. Lighting Heat Gains and Loads
Energy Simulation for Commercial Buildings
Page ‐ 156 -
2015 June 22
[ENERGY SIMULATION]
When using programs that employ the Transfer Function Method, remember that nearly all loads
involve dynamic heat flow. Heat gain received from a source such as lighting is not immediately
converted to a cooling load. Rather, the portion of the heat gain that is thermal radiation is
transferred to massive building elements such as floors and walls, and may be stored for a period
of time before being released to air in the building. Once heat is transferred to the air, it is a load
that must be removed by the air conditioning apparatus. Figure 2 shows a sample relationship
between lighting heat gain and load. When the lights first come on, a significant portion of the
lighting heat gain is absorbed and held by the building mass. Over time, this stored heat is
discharged to air in the building, but more radiant heat is received. When the lights are turned off,
the stored heat continues to be discharged. Thus, loads continue even after the heat gains
cease. All heat sources that involve a radiant component exhibit similar behavior. These include
loads for walls, roofs, windows, partitions, people, lights and electrical equipment. Transfer
Function calculations account for these dynamic processes. Remembering this is often very
helpful when analyzing load calculation outputs.
The Radiant Time Series method was introduced in ASHRAE 2001 Handbook of Fundamentals.
It is a dynamic way of calculating loads, but is not as complex to calculate and is easier to
understand than the TFM. It is a good method to obtain sizing data for a typical building.
However, it is not a good method to simulate system operation. 
Energy Simulation for Commercial Buildings
Page ‐ 157 -
2015 June 22
[ENERGY SIMULATION]
The Benefits of the Transfer Function / Heat Extraction Method
The previous article (Putting Load Calculation Methods in Perspective) describes the transfer
function and heat extraction procedures used to calculate loads in HAP. While the benefits of this
calculation method for energy analysis are evident, customers often question whether such
advanced calculation methods are worth using for system design applications, or whether simpler
methods would be sufficient. Carrier feels that advanced methods such as transfer functions/heat
extraction should be used because the method provides several important benefits to users.
These include:
1.
Accuracy. Advanced methods such as Transfer Functions account for the dynamic heat
flow processes which occur in buildings and which significantly influence design loads and
system behavior. Simpler methods either ignore these dynamics, or analyze them in much less
detail than Transfer Functions. Advanced methods therefore can provide results that are more
accurate.
2.
Pull down Loads. One of the most important aspects of dynamic heat flow is the pull
down load. Pulls down loads have a significant influence on system sizing results and therefore
need to be considered. Advanced methods such as Transfer Functions/Heat Extraction are the
only way to adequately account for pull down loads. Simpler methods can only make gross
estimates of the effect of pull down loads.
3.
Flexibility. Advanced methods such as Transfer Functions/Heat Extraction customize
calculations to the application. Since loads are dynamic, loads in one hour are influenced by
conditions in both the current hour and previous hours. The nature of 24-hour profiles of solar
radiation, ambient temperature and internal heat gain need to be considered to accurately predict
loads in any one hour. Transfer functions use the solar, temperature and internal gain profiles
defined by the user for each specific application. Therefore, loads are customized to each
application. Simpler table-based methods make assumptions, such as a standard operating
profile or the use of July 40°N latitude for solar radiation. In some cases, correction factors are
used to try to adjust for actual conditions. These adjustments are often not adequate and
produce less accurate results than methods that customize calculations to each application. 
Understanding Zone Loads and Zone Conditioning
Have you ever examined a HAP Air System Design Load Summary output and wondered ‘what is
zone conditioning and why it differs from the total zone load?’ Judging from questions our
support staff receives, many people have wondered the same thing. The answer to this question
requires an explanation of the ASHRAE Transfer Function and Heat Extraction methods.
Understanding the calculation methods used by computerized engineering tools is vital to the
successful use of these tools. As these tools use increasingly complex analytical methods, the
methods become more difficult to grasp. This article attempts to aid understanding of the load
calculation method used in Carrier’s Hourly Analysis Program (HAP) by explaining the transfer
function and heat extraction methods in plain language and without the use of mathematical
equations. If at the end of this discussion you understand what “zone conditioning” and “zone
load” refer to and why they are different, the article will have been successful.
Objectives. First, we need to clarify our objectives for a load calculation tool. As HVAC system
designers, we want:




A calculation tool that accounts for all the processes involved with building heat flow,
A tool that is fast,
A tool that is easy to use, and
A tool that provides accurate, reliable results.
Energy Simulation for Commercial Buildings
Page ‐ 158 -
2015 June 22
[ENERGY SIMULATION]
Understanding the Processes at Work. Providing accurate, reliable results requires accounting
for all of the complicated heat flow processes occurring in the building. For the explanations of
the Transfer Function and Heat Extraction Method later in this article to make sense, we first
need to provide a quick refresher on the heat flow processes that occur in a building.
First, our ultimate interest is in cooling or heating loads. A “load” is the rate of heat transfer to or
from the air in the building. Heat transferred to air in a room changes the room air temperature.
The thermostat senses these changes and sends a signal to the HVAC equipment to provide
cooling or heating.
Secondly, we are all familiar with the different sources of heat gain or loss, which influence
cooling or heating demands in the building. These include solar radiation, temperature gradients
across walls, heat gain from lighting, people, etc.
Therefore, we know where the heat originates (the sources) and we know where it ultimately
ends up (in the air in the building). The challenging part of this engineering problem is analyzing
how heat travels from its source to its destination.
As an example, let us consider the wall component of a cooling load. First, solar radiation and
ambient air warm the outside surface of the wall. This initiates heat flow across successive layers
in the wall assembly. Heat does not flow instantaneously from outside to inside surfaces of the
wall. Instead, it takes time. In addition, the amount of time depends on the intensity of heat flow at
the outer surface plus the thickness, density, specific heat and thermal conductivity properties of
material layers in the wall assembly.
Ultimately, heat reaches the inside surface of the wall where it raises the wall surface
temperature. At this point two things happen. First, a portion of the heat convects to air in the
room, raising the air temperature. Thus, this heat becomes a cooling load. Second, a substantial
portion of the heat at the wall surface transfers as thermal radiation to other wall, ceiling and floor
surfaces in the room. This raises the temperature of the other surfaces and triggers convection to
room air, heat storage within the material and further radiative exchanges within the room.
Eventually most or all of the original heat flow becomes a cooling load, but the complete
conversion of the heat gain to cooling load takes time.
The same sort of thermal processes occur for heat flow through roofs, windows, doors and
partitions. Heat from other sources such as solar, lighting, electrical equipment and occupants is
introduced directly into the room, and once in the room it undergoes the same sort of room heat
transfer processes described for walls. This is because all these heat gains are comprised of
separate convective and radiative components. The convective components immediately become
cooling loads. The radiative components transfer directly to surfaces in the room and then
undergo further radiant, convective and heat storage processes.
Another important factor governing heat flow to the air in the room is the temperature of the room
air. The temperature difference between wall, ceiling and floor surfaces and the room air govern
convection. Thus, for a cooling scenario, convective heat flow from warm room surfaces
decreases as the room air temperature rises. As room air temperature falls, convective heat flow
from warm room surfaces increases. Recognizing this is important for two reasons. First, all
thermostats have a certain operating range within which they attempt to maintain room air
temperature. Thus, room air temperature varies within this operating range and this influences
convective heat flow. More importantly, nighttime setup control or equipment shutdown can cause
room temperature to vary by 10 °F (-12.2 °C) or more during a 24-hour operating cycle. A large
increase in room temperature greatly reduces convective heat flow. Heat is essentially “trapped”
in the massive elements in the room, and the surface temperatures of these elements rise. In the
morning when cooling equipment starts up reducing room air temperatures, there is a “rush” of
convective heat flow due to the large temperature difference between room air and the surfaces
in the room. We call this process “pull down load.”
Energy Simulation for Commercial Buildings
Page ‐ 159 -
2015 June 22
[ENERGY SIMULATION]
Therefore, in summary:




There are many factors involved in building heat flow.
This heat flow occurs over time rather than instantaneously.
Room air temperature governs heat flow from surfaces in the room to the air in the room.
The nature of the thermostat control in a room influences the rooms cooling loads by affecting
convective heat flow.
Calculating Building Heat Flow. Now, in order to calculate realistic, accurate building loads, we
need to account for all of the complicated processes we have just discussed. This is quite a
challenge. One way to do this is with the “Heat Balance Method” which is essentially the “mother
of all load calculation methods.” With this method, each of the heat flow processes is represented
by a mathematical equation drawn from the laws of conduction, convection and radiation and
from the first law of thermodynamics. The result is a large number of equations, and an equally
large number of unknown quantities. Typically, no one equation can be solved directly. Instead,
the whole set of equations must be solved simultaneously or by iteration. The results of this
calculation are the temperatures and heat flows at each surface in the room, and ultimately the
temperature and heat flow to room air, which tells us the cooling load. Currently, we cannot
satisfy our original objectives of “fast” and “easy” with the Heat Balance Method because
computer software using this method requires too much calculation time and too much input data.
However, the day is fast approaching when this method will become feasible for everyday use on
desktop computers.
Until then, we need an alternate solution to our engineering challenge. That solution is the
Transfer Function Method, first developed by researchers in the late 1960s. The Transfer
Function Method uses several mathematical “tricks” to make solving heat balance equations
much faster. While this method is faster, it continues to account for the complex processes
involved in building heat flow and thus provides realistic, accurate results.
Here is how it works. Within the method, there are three kinds of transfer function equations used
to analyze different aspects of the building heat flow problem:

HAP uses Conduction Transfer Function Equations to analyze the conductive heat flow
through walls and roofs.

HAP uses Room Transfer Function Equations to analyze the radiative, convective and
heat storage processes for all load components once heat reaches the interior of the room.

HAP uses Space Temperature Transfer Function Equations (aka. Heat Extraction
Equations) to analyze the effect of changing room temperatures on convective heat flow from
surfaces in the room to the room air. Included in this calculation is the behavior of the room
thermostat in controlling room temperature levels and communicating demands to the cooling
or heating apparatus.
Using these three kinds of transfer function equations in sequence determines how heat from
various heat sources converts into cooling loads in the building.
However, there is one complicating factor crucial to this whole discussion. It has been said that
there is “no such thing as a free lunch,” and that is certainly true in this case. As we noted earlier,
the Transfer Function Method uses mathematical tricks to simplify and speed up the calculation
process. The cost of increased speed is performing the calculation in two distinct stages. There
are simply too many factors involved to be able to solve the entire problem in one pass when
using the transfer function tricks.
In the first stage of this calculation process, we use the Conduction and Room Transfer Function
Equations to calculate room loads as if the room is held at precisely one temperature 24 hours a
day. For a design cooling calculation, we use the cooling thermostat set point as the fixed room
temperature for this calculation. Once room loads based on this simplifying assumption have
Energy Simulation for Commercial Buildings
Page ‐ 160 -
2015 June 22
[ENERGY SIMULATION]
been determined, the second calculation stage “corrects” these loads to account for the true
behavior of the building (rising and falling room temperatures) using the Space Air Transfer
Function Equations.
In HAP, results of these two calculation stages appear throughout the system design reports. On
the Air System Design Load Summary, all the results in the top portion of the report down to and
including the “Total Zone Load” are from the first stage of the calculation, which assumed
constant room temperature. We use the terms “zone load” and “space load” throughout the
reports to refer to results from this first stage of calculations. We use the term “Zone Conditioning”
to refer to the results of the second stage of calculations. HAP corrects the “Total Zone Loads” to
produce “Zone Conditioning” by accounting for room temperature and thermostat effects. As
such, Zone Conditioning represents the true amount of cooling or heating a room needs and is
the basis for simulating operation of system components such as coils and fans. Results from the
system simulation appear in the lower part of the Air System Design Load Summary. Differences
between “Zone Loads” and “Zone Conditioning” are due to room temperature effects on heat
transfer such as pull down loads and temperature variations within the thermostat throttling range.
Conclusion. The Transfer Function Method allows us to consider as many of the complex
aspects of building heat flow as possible to provide accurate results, and at the same time
provide a calculation tool that is fast and easy to use.
The price for these benefits is that we must perform the calculation in two distinct stages. The first
stage yields what HAP calls “zone loads” and “space loads” assuming a constant room
temperature. The second stage yields what HAP calls “zone conditioning” which is derived by
correcting the original zone loads to account for room air temperature effects. Zone conditioning
represents the true demand for cooling or heating in a zone. Understanding this two-stage
process and the results it yields is important for successfully applying program results.
Energy Simulation for Commercial Buildings
Page ‐ 161 -
2015 June 22
[ENERGY SIMULATION]
The Sizing Dilemma
In HAP, users are asked to choose among four different methods of sizing zone and space
airflow rates. This discussion explains why different sizing methods are used and summarizes the
four methods offered in the programs.
The Sizing Dilemma. The key issue is that there is not a single “correct” way to size space
airflow rates. In fact, no sizing method can guarantee comfort in all spaces at all times when a
zone contains multiple spaces. The reason for this is that each zone has a single thermostat to
control the comfort conditions in all the spaces in that zone. The space that contains the
thermostat will maintain comfort conditions, but the other spaces in the zone will receive
conditioning based on the load in the space containing the thermostat. Because of this imperfect
situation, designers’ use different approaches to size space airflow rates in order to minimize
conditioning problems in the spaces that do not contain the thermostat. Which approach is best
varies by application. Ultimately, the choice of a sizing method depends on the designer’s
judgment and experience.
Sizing Method #1:


Zone airflow computed using peak zone load.
Space airflow computed using zone CFMft² or L/s/m².
With this method, the zone airflow is computed using the maximum zone sensible cooling load.
The zone airflow is divided among spaces in the zone on the basis of zone CFM/ft² (L/s/m²).
Therefore, space airflow is not related to space loads unless all spaces in the zone have a
consistent load density in BTU/hr/ft² (W/m²).
Sizing Method #2:


Zone airflow computed using peak zone load.
Space airflow computed using coincident space loads.
With this method the zone airflow is calculated from the maximum zone sensible cooling load.
The zone airflow is divided among spaces in the zone on the basis of the ratio of coincident
space sensible cooling loads to peak zone sensible load. By “coincident,” we mean the space
load computed for the month and hour when the zone sensible load peaks.
Sizing Method #3:


Zone airflow computed using peak zone load.
Space airflow computed using peak space load.
With this method, the zone airflow is computed using the maximum zone sensible load. Required
space airflow rates are computed using the maximum sensible load for each individual space.
Note that if spaces experience peak loads at the same time the zone peak occurs, the sum of
space airflow rates will equal the zone airflow rate. Otherwise, the sum of space airflows will
exceed the zone airflow rate.
Sizing Method #4:


Zone airflow computed using sum of space airflows.
Space airflow computed using peak space load.
With this method, required space airflow rates are computed using the maximum sensible load for
each individual space. The zone airflow rate is calculated as the sum of space airflows for all
spaces in the zone.
Energy Simulation for Commercial Buildings
Page ‐ 162 -
2015 June 22
[ENERGY SIMULATION]
Which Sizing Method to Use?
By John Deal, Regional Sales Manager, Carrier Software Systems.
The previous article titled The Sizing Dilemma discusses in detail the four sizing methods in HAP.
The problem confronting the designer is that one of the four methods must be chosen and some
thought is required to determine which method to use. The purpose of this article is to share
some ideas to assist your decision on which sizing method to use.
The four methods summarized in the previous article (The Sizing Dilemma) are those requested
by our HAP customers. If someone has another sizing method, we certainly would like to hear
about it! I think we can safely say that every designer uses one of these methods almost
exclusively and probably was not aware of the three alternatives until forced by an impudent
software program to make a choice. The method one uses is probably from a habit formed when
a load estimating methodology and calculations were first learned or passed on from a teacher, a
mentor or a boss.
Methods 1 and 2 give results similar to those of “hand” calculation methodology expectations.
Simplifying assumptions were made because of the amount of time it took to perform the number
crunching. One could not afford the time necessary to calculate loads over a number of hours or
to break up the building into numerous design zones and spaces. So, results were obtained in a
simplified fashion that could be easily applied throughout the design such as CFM/ft² (L/s/m²),
heat loss of BTU/hr/linear ft. (W/m) of exposure and so forth.
Methods 3 and 4 give results expected of a methodology that can only be done on a computer.
Calculating 12 months 24 hours a day to find peak loads for fans, coils, zones and spaces is a
reasonable expectation. Crunching the numbers on hundreds of spaces collected into a hundred
or more zones in a dozen air systems is a reasonable expectation.
I am going to make a provocative statement to start your thought process on which methods to
use. If you are doing detailed final design calculations, methods 3 and 4 are the ones to use and
the type of system under design will dictate which one. Variable air volume (VAV) systems use
method 3. Constant volume systems use method 4.
The key function that these two methods share is that the space peak sensible load is found and
reported. This gives the designer the information about the peak design parameters for every
space defined. With this information, the designer can get a better handle on the magnitude of the
compromises that must be made with the control zone layouts, duct design and terminal
equipment sizing.
Using method 3 for a VAV terminal zone sizes the “box” for a VAV diversified CFM. The spaces in
the zone are sized for their peak so no matter which space the thermostat is placed in that space
can be controlled. If future reworking of zones is done, the space duct and terminal sizing is still
valid. The key to good zoning practice is to have spaces with similar thermal load profiles on the
same thermostat. With this method the time and month that each space peaks is reported. This
helps in the decision whether the spaces have similar thermal load profiles. If all the spaces in the
zone peak in the same month around the same time of day, this indicates a good probability of
similar thermal load profiles for the spaces. If one or more spaces peak at different times of the
year than the other spaces this indicates dissimilar load profiles and some thought should be
given to “re-zoning."
Energy Simulation for Commercial Buildings
Page ‐ 163 -
2015 June 22
[ENERGY SIMULATION]
Using method 4 for constant volume systems is good practices since these types of systems are
normally not sized with diversified or block load air quantities. Let us discuss one of the most
common systems, the packaged rooftop unit. In HAP language, this is a single zone constant air
volume system. If the designer takes the time to describe the various areas served as spaces,
some valuable information can be gained. An example is the amount of air needed in different
places so diffusers and the duct system can be designed with some knowledge of the actual
requirements. Again, if some of the spaces were peaking at different times of the year than others
this would indicate the need for better zoning (another unit if you can afford it). At least you will
know that the job probably will not work very well at this stage. This method also sizes the rooftop
unit CFM (L/s) undiversified. This is good since it seems you need to get all the air you can on
these types of jobs.
We hope that this article has helped you think about the choices of space descriptions, zoning
and sizing methods you must make. Make your choices with a purpose in mind. I am sure many
of you may have differing thoughts and we would like to hear them. Even with faster computers
and more complex software, system design still has a lot of art and designer experience involved.
Remember this old saying: If a job is to work correctly, it must be designed right one time. The
problem is when! 
Energy Simulation for Commercial Buildings
Page ‐ 164 -
2015 June 22
[ENERGY SIMULATION]
Differences between Peak Coil Load CFM, Max Block CFM, Sum of Peak
Zone CFM
In the cooling coil section of the HAP Air System Sizing Summary printout, three coil airflow rates
are listed: (1) the coil airflow for the time when the maximum coil load occurs, and (2) the
maximum block airflow rate and (3) sum of the peak zone CFM (L/s). When analyzing VAV
systems, these three airflow rates can often differ. This article explains why. An accompanying
article provides recommendations for selecting equipment in these situations.
In most cases, the coil airflow rates differ in VAV applications for one of the following two
reasons:
The peak cooling coil load and peak zone sensible load occur at different times, resulting in
different coil airflow rates at these times.
Due to the ASHRAE sizing methodology used by HAP, the two airflow rates are computed using
slightly different considerations. This can introduce small differences between the two airflow
values even if the coil load and zone sensible load peak at the same time.
Each reason will be explained separately below.
Differences Due to Timing of Peak Loads. The maximum airflow rate required for the supply
fan and therefore for the central cooling coil depends on the cooling requirements in zones
served by the air system. The individual component loads in the zones such as wall, roof,
window, solar, lighting, people and equipment loads influence zone cooling requirements. These
loads vary due to changes in outdoor air temperature, solar radiation and internal heat gains
throughout the day.
While the maximum cooling coil load is influenced by these same zone cooling requirements, it is
also influenced by extra heat gains introduced by outdoor ventilation air, fan heat, return plenum
heat, and the latent components of the coil load.
Because extra factors influence the coil load, it is possible for the maximum coil load to occur at a
different time than the peak zone sensible load occurs.
In a VAV system, the coil airflow varies as zone cooling requirements vary. Therefore, if the peak
cooling coil load and peak zone sensible load occur at different times, the coil airflow rates for the
two times will differ. The following simple example illustrates how this situation can occur.
Example #1. Consider a 1-zone VAV system that serves an east-facing zone. Figure B-3 shows
24-hour profiles for the total cooling coil load and the zone sensible load for this system. The
zone has a large area of east-facing glass. Consequently, solar heat is the dominant load
component and causes the peak zone sensible load to occur at 9 am.
The total cooling coil load in this example is strongly influenced by ventilation loads, which peak
during the mid-afternoon hours. Since the outdoor air temperature is relatively cool at 9 am
versus mid-afternoon, the peak coil load occurs at 2 pm rather than 9 am. When the peak zone
sensible load occurs at 9 am, the zone requires 5154 CFM of supply air. When the cooling coil
load peaks at 2 pm, the zone sensible load has dropped to approximately 80% of its peak value
and the zone requires only 4100 CFM of supply air. For such a situation, HAP will report the
following data on the Air System Sizing Summary output
Peak coil load occurs at:
Jul 1400
Coil CFM (L/s) at Jul 1400:
4100 CFM (1935 L/s)
Maximum block CFM (L/s):
5154 CFM (2432 L/s)
Sum of peak zone CFM (L/s)
5369 CFM (2534 L/s)
Energy Simulation for Commercial Buildings
Page ‐ 165 -
2015 June 22
[ENERGY SIMULATION]
The Sum of the peak zone CFM (L/s) is useful for judging diversity in VAV systems and for sizing
components for special periods when all VAV box dampers are full open at the same time.
Differences Due to Methodology. The ASHRAE design procedure, which utilizes the transfer
function method and heat extraction techniques, requires a two-stage calculation:
1.
First, zone sensible loads are computed assuming the zone is held exactly at the cooling
thermostat set point 24 hours per day. Results from this analysis are used to determine peak
zone airflow rates and the peak central coil airflow rate.
2.
Second, the program simulates system operation. When doing so, it takes the zone loads
calculated in the first stage and corrects them for the actual system operating conditions. These
corrections account for the use of different thermostat set-points during occupied and unoccupied
periods or the shutdown of cooling during the unoccupied times, and for the existence of a
throttling range for the thermostat. Considering these real-life system-operating factors changes
the thermal dynamics of the system, causing zone temperatures to vary within the thermostat
throttling range and introducing pull-down load components at certain times of day.
The "Max block CFM (L/s)" is calculated in stage 1 and is therefore based on the idealized zone
loads computed in this stage. The coil airflow at the peak coil load time is obtained from stage 2,
and is therefore based on the corrected zone loads computed considering the actual system
operating conditions. Because the two airflows are computed using slightly different
considerations, differences between the two airflows often occur for VAV systems. The following
example illustrates these method-based effects.
Figure B-3 Stage One Calculations
Energy Simulation for Commercial Buildings
Page ‐ 166 -
[ENERGY SIMULATION]
2015 June 22
Figure B-4 Stage Two Calculations
Example #2. Consider a VAV system that serves four zones. Hourly profiles of the total coil load
and the zone sensible block load are shown in Figure B-4. Here "block load" refers to the sum of
the sensible loads for all four zones. The maximum zone sensible block load occurs at 5 pm in
July. Based on this block load, the required coil airflow rate is 13269 CFM (l/s.) The maximum
cooling coil load also occurs at 5 pm in July. For this hour the coil airflow rate is 12355 CFM (l/s.)
Therefore, on the Air System Sizing Summary, HAP will report:
Peak coil load occurs at
Jul 1700
Coil CFM (L/s) at Jul 1700 12355 CFM (L/s)
Max block CFM (L/s)
13269 CFM (L/s)
In this example, the 900 CFM (425 L/s) difference between airflows is due to the different
considerations used to calculate the required fan airflow in stage 1 of the analysis, and the coil
airflow during the system simulation in stage 2 of the analysis. Further investigation of the results
showed that the zone air temperatures are close to 76° F (24.4° C), which is the upper limit of the
thermostat throttling range for this example. For the initial zone loads calculated in stage 1 of the
analysis, a thermostat set-point of 75° F (23.9° C) was used. The difference in zone air
temperatures used in the two calculations (75° F [23.9° C] versus 76° F [24.4° C]) and its effect
on zone thermal dynamics ultimately results in lower coil airflow.
The important thing to recognize is airflows are computed for different purposes and therefore
use different considerations. The maximum coil airflow is derived as part of the zone and fan
airflow sizing calculation, which considers idealized conditions. The coil airflow at the time of the
peak coil load is derived as part of the cooling coil analysis. This analysis considers all of the
operating factors of the system, most notably the interaction between the zone thermostats and
the VAV box dampers, and between zone air temperature and room loads.
Energy Simulation for Commercial Buildings
Page ‐ 167 -
2015 June 22
[ENERGY SIMULATION]
Further Information. Differences between maximum coil airflow rate and coil airflow rate for the
peak coil load time can also occur for Multizone, Bypass Multizone and Dual Duct CAV systems,
and for single-zone constant volume systems using fan cycling.
Selecting Equipment When Coil CFM (L/s) Differ
The preceding article describes situations in which the maximum coil airflow rate differs from the
airflow rate at the time of the peak cooling coil load. When this happens, a design engineer is
faced with the dilemma of which airflow rate to use when selecting equipment. This article
provides recommendations for dealing with this equipment selection situation.
Central Cooling Coils in VAV Systems.
First, the packaged unit or the cooling coils for a built-up unit should be selected using the airflow
at the time of the peak coil load [listed as "Coil CFM (L/s) at month/hour"]. This airflow is obtained
from the system simulation and corresponds to the total load, sensible load, and entering and
leaving temperature conditions in the table. Thus, in order to use consistent coil performance
data for selection, the "Coil CFM (L/s) at month/hour" item must be utilized.
Second, use the fan motor BHP or fan motor kW data reported in the "Supply Fan Sizing Data"
section of the Air System Sizing Summary to select the fan motor.
Third, verify that the selected fan can operate at the maximum fan airflow rate without exceeding
its maximum RPM value. The maximum fan airflow is reported in two places on the Air System
Sizing Summary. It appears in the "Central Cooling Coil Sizing Data " table as "Max block CFM
(L/s).” It also appears in the "Supply Fan Sizing Data” table as "Actual max CFM (L/s)". The Sum
of peak zone CFM (L/s) is provided for those who wish to take further precautions.
Finally, in certain applications, it may be necessary to use product literature to verify that
excessive water carry-over will not occur when the coil experiences its maximum airflow rate.
Recommendations for Other System Types.
Differences between the maximum coil airflow and the coil airflow at the peak coil load time can
also occur for Multizone, Bypass Multizone, and Dual Duct CAV systems. For these systems, the
cooling coil should be selected using the airflow at the peak coil load time. Make sure the coil will
not have excessive water carryover when operating at maximum airflow. To select the fan, the
maximum fan airflow should be used since the fan supplies air to both cold and hot decks.¨
Energy Simulation for Commercial Buildings
Page ‐ 168 -
2015 June 22
[ENERGY SIMULATION]
ASHRAE 62.1-2004 and 2007 Ventilation Air Sizing in HAP
This article explains how to define the ASHRAE 62.1-2004 and 2007 ventilation requirements in
HAP 4.6. We also discuss differences between Standard 62.1-2004/7 and Standard 62-2001
with respect to space usage and outdoor air requirements. We also explain how HAP determines
the minimum system ventilation (outdoor air) requirement per 62.1-2004/7 at the space level and
then at the system level which is the OA intake of the HVAC unit. We end our discussion
reviewing the HAP Ventilation Sizing Summary Report for a VAV system using ASHRAE
Standard 62.1-2004/7 procedures.
HAP e-Help # 006 titled “Ventilation” dated November 2, 2005 is prerequisite reading to this
discussion. It examines ASHRAE Standard 62-2001, and “user defined” ventilation sizing method.
It explains the hierarchy employed by the software in determining the ventilation air requirements
of the HVAC system. We also explain ventilation airflow controls, which including constant,
proportional, scheduled and DCV (demand controlled ventilation).
ASHRAE Standard 62
Since its introduction, Standard 62 from the American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE) has been the primary design reference affecting the
ventilation aspects of HVAC systems. ASHRAE Standard 62.1-2010, is the most recent
ventilation standard. As shown below, the standards for ventilation air have evolved over the
years to accommodate the changing design trends in the industry.
Figure C-1 Evolution of ASHRAE Ventilation Standards
Energy Simulation for Commercial Buildings
Page ‐ 169 -
2015 June 22
[ENERGY SIMULATION]
The purpose of ASHRAE 62.1-2004/7, is to specify minimum ventilation rates to help achieve
acceptable indoor air quality. Since we can dilute contaminants in indoor air by supplying the
space with uncontaminated outdoor air, ASHRAE established ventilation rates in Standard 62.12004/7 based on achieving this dilution. ASHRAE 62.1-2004/7 considers these minimum dilution
requirements as good design practice for achieving acceptable indoor air quality.
Defining ASHRAE Standard 62.1-2004/7 Ventilation Requirements in HAP
In HAP, we use the preferences option on the “View” Menu to specify preferences affecting the
project operation such as ventilation. See figures C-2 and 3 below to set preferences. HAP
includes the following choices for ventilation calculations:
User Defined
ASHREA Standard 62-2001
ASHRAE Standard 62.1-2004
ASHRAE Standard 62.1-2007
Figure C-2 HAP Preferences
Figure C-3 Setting Project Preferences
Energy Simulation for Commercial Buildings
Page ‐ 170 -
2015 June 22
[ENERGY SIMULATION]
Space Level Ventilation in ASHRAE 62.1-2004 & 2007
After choosing the ASHRAE ventilation Standard, HAP defaults to the specific Space Usage
options and associated OA requirements that comply with that Standard. For example in Figure
C-4, the Space Usage options displayed in the Space Properties input screen reflect specific
values from ASHRAE Standard 62.1-2007. The note at the bottom of the Space Properties form
serves as a reminder of the chosen ventilation standard.
Figure C-4 HAP Space Properties Input Screen (General Tab)
ASHRAE Standard 62.1-2004 revised the outdoor air requirements for various types of space
usages. The Standard also completely overhauled the methods for determining minimum outdoor
air airflow rates. Figure C-5 shows a partial table of minimum ventilation rates at the breathing
zone for different occupancy categories. Let us examine the differences between Standard 622001 and Standard 62.1-2004/7.
Figure C-5: Minimum Ventilation Rates ASHRAE 62.1-2004
Energy Simulation for Commercial Buildings
Page ‐ 171 -
[ENERGY SIMULATION]
2015 June 22
Space Usage Comparisons and Two-Part OA Requirement
ASHRAE 62.1-2004/7 determines the total outdoor airflow rate for the system using the
Ventilation Rate Procedure from Section 6.2 and Appendix A in the Standard. This procedure
involves a two-part OA requirement. The first part determines CO2 generated pollutants or odors
based on number of occupants. The second part determines pollutants generated by building
materials and VOC in the space based on square feet floor area. In contrast, Standard 62-2001
requires just a one-part OA requirement as shown below.
Differences exist in the space usage categories between the two Standards. Figures C-6 and C-7
offer visual comparisons between Standard 62-2001 and 62.1-2004/7 for Retail and Education
space usage categories.
ASHRAE 62-2001
ASHRAE 62.1-2004/2007
Figure C-6: RETAIL Space Usage Comparison
Energy Simulation for Commercial Buildings
Page ‐ 172 -
2015 June 22
[ENERGY SIMULATION]
Figure C-7 below shows space usage comparisons in the EDUCATION category. Notice the
quantity of space usage choices remained the same, but space usage names differ in Standard
62.1-2004/7 vs. 62-2001.
ASHRAE 62-2001
ASHRAE 62.1-2004
Figure C-7: EDUCATION Space Usage Comparison
Energy Simulation for Commercial Buildings
Page ‐ 173 -
[ENERGY SIMULATION]
2015 June 22
The procedure for calculating space and project level ventilation airflow in Standard 62.1-2004/7
involves two (2) major steps. The first major step considers the following three (3) steps in
determining total space ventilation rates:
Summing the CFM/person and CFM/ft² requirements as discussed above.
Applying time averaging to space occupancy.
Utilizing space air distribution effectiveness.
The second major step determines how much outdoor ventilation air the central system intake
requires in ensuring each space receives the required ventilation. As we will see, the ventilation
airflow required at the intake can be larger than the sum of the uncorrected space OA airflows.
The second item determined in step two (2) is the final total ventilation requirement at the air
intake using the calculated system ventilation efficiency.
Before we continue, we should clarify some terminology between HAP and ASHRAE. ASHRAE
Standard 62.1-2004/7 uses “zone” to refer to what HAP identifies as a "space". To avoid
confusion, this discussion adopts the HAP terminology. For example and clarity, later in this
discussion the Standard refers to "zone ventilation efficiency" to which HAP refers as "space
ventilation efficiency".
Step 1: Determining the Space Level Minimum Ventilation Requirements
1. Summing the OA Requirements
During sizing calculations for Standard 62.1-2004/7, HAP first sums the two OA requirements.
However, at this point in the calculations we must apply the additional considerations mentioned
above. For that reason it is difficult to say which Standard (62-2001 or 62.1-2004/7) requires the
greater ventilation air volume before doing all the calculations.
Using our 840ft² classrooms with 25 children from Figure C-7, the “uncorrected” ventilation air
requirements are:
Standard
Space Usage Category
Calculation
Uncorrected
Ventilation Air
62-2001
Classroom
25  15CFM/Person
375 CFM
62.1-2004
Classroom (ages 9+)
25  10CFM/Person
250 CFM
+ 0.12 CFM/ft²  840 ft²
101 CFM
Standard 62-2001 requires 375 CFM of uncorrected ventilation air versus 351 CFM for 62.12004/7. Uncorrected means we must still apply additional considerations or “adjustments” as
required by the Standard.
Energy Simulation for Commercial Buildings
Page ‐ 174 -
2015 June 22
[ENERGY SIMULATION]
2. Calculating the Time Averaging Factor
If the number of people in the space fluctuates over time, Standard 62.1-2004/7 allows estimating
the space population by applying a time averaging procedure. HAP applies the user’s fractional
people schedule along with the equations in paragraph 6.2.6.2 of ASHRAE Standard 62.1-2004/7
to produce a “time averaging interval”. The interval length is a function of the ventilation air
change for the space. HAP uses the calculated average occupant values for this interval and
uses the largest average value in determining the time averaging factor. HAP uses this factor to
correct the OA per person ventilation amount.
For example, suppose a 2000ft² space with floor to ceiling height of 9 ft. has 10 occupants. The
requirements for this space are 5 CFM/person and 0.06 CFM/ft². Using 10 occupants and 2000
ft², the uncorrected outdoor airflow is 170 CFM. The time averaging interval equation from the
Standard is 3 x Space Volume / uncorrected outdoor airflow, which equals 318 minutes or 5.3
hours. HAP rounds this to 5 hours. Next, HAP calculates an average schedule factor for each
group of five (5) consecutive hours in the people design day schedule. First HAP uses hours
0000 thru 0400, then 0100 thru 0500, then 0200 thru 0600, etc. If the schedule values for five
consecutive hours are 60%, 80%, 100%, 100% and 100%, the average for this block is 88%.
Once HAP calculates these averages for each 5-hour block in the day, HAP uses the largest
average as the Time Averaging Factor. In this case, since the largest 5-hour time averaged
occupancy is 88% means the people count is 0.88 X 10 = 9 occupants. If we take 5 CFM/person
X 9 people, we have 45 CFM versus 50 CFM as initially determined, resulting in a reduction of 5
CFM for the space and 165 CFM instead of 170 CFM as the sum of the 2-part OA requirement.
If the people schedule uses 100% for all hours, the Time Averaging Factor is 100%. Also, note
HAP uses only CFM/person and CFM/ft² airflow requirements for this calculation. If you have
specified a total airflow (CFM) or "% of supply airflow" ventilation requirement for the space, HAP
does not consider these values in the calculation as they are outside the scope of the Standard
62.1-2004/7 Ventilation Rate procedure.
The time averaging factor does not always result
in a downward correction of the people
occupancy and an associated decrease in
ventilation airflow. It depends on the space
volume, people occupancy, and profile. For
example, the 840ft² classroom with 25
occupants, requires 10 CFM/person and 0.12
CFM/ft² resulting in 351 CFM uncorrected
outdoor airflow. The time averaging interval from
the ASHRAE equation is 3 x Space Volume /
351 CFM, which equals 60 minutes or 1 hour. In
this example, the program calculates an average
schedule factor for each one consecutive hour.
The largest one-hour “average” in this case is
100%, so for this classroom there is no change
to the original uncorrected ventilation airflow
based on the time averaging factor.
Energy Simulation for Commercial Buildings
Figure C-8 People Profile For Classroom
Page ‐ 175 -
[ENERGY SIMULATION]
2015 June 22
3. Assigning Space Air Distribution Effectiveness
The next consideration affecting the required space outdoor airflow amount involves the air
delivery from the diffusers. The Air Distribution Effectiveness is a new concept in ASHRAE 62.12004. It is not enough to deliver ventilation air to a space, that air must also effectively reach the
breathing zone of its occupants. Standard 62.1-2004/7 state, “A system that is effective at
delivering air to the breathing zone requires less outdoor airflow than a less effective one for the
same space”.
The Standard defines the breathing zone as the area between 3 in and 72 in above the floor as
shown in Figure C-9. When supply air is delivered anywhere above the breathing zone, it is
considered to be the same as ceiling delivery. Since different types of systems and air terminals
are more or less effective at delivering ventilation air to this breathing zone, HAP considers the
effectiveness of the air distribution system in calculating ventilation requirements.
Most cooling applications deliver the air through ceiling diffusers thus using an effectiveness
value of 1.0. If cooling sidewall supply registers are more than 72 inches above the floor, HAP
considers them the same as "ceiling supply" with an effectiveness value of 1.0.
Figure C-9 Space Air Distribution Effectiveness
Per ASHRAE 62.1-2004/7, systems that deliver warm air from a ceiling supply diffuser, and
have supply air 15 °F above room air temperature, have an effectiveness of 0.8. Warm air
supplied from a ceiling diffuser, with a temperature <5 °F above room air temperature have an
effectiveness of 1.0.
HAP performs the Standard 62.1-2004/7 calculations twice for each system if the system
provides cooling and heating. It performs it once assuming cooling operation and again for
heating operation. HAP uses the larger system ventilation airflow as the result. If heating duty
results in a larger ventilation airflow, then the space air distribution effectiveness HAP uses is
0.8 (reflecting warm air supply typically 15 °F above room temperature) for all spaces in the
system.
Energy Simulation for Commercial Buildings
Page ‐ 176 -
2015 June 22
[ENERGY SIMULATION]
The outdoor air amount for the space calculation is found by dividing the uncorrected airflow by
the space air distribution effectiveness, which occurs after the time averaging correction.
Standard 62.1-2004/7 refers to answer as "zone outdoor airflow" after considering the space
air distribution effectiveness.
Step 2: Determining the System Level Minimum Ventilation Requirements
Step 2 determines how much outdoor ventilation air is required at the common OA intake to
ensure that each space receives its required ventilation. As we will see, the ventilation airflow
required at the intake can be larger than the sum of the uncorrected space airflows due to
issues related to the “critical space”. Determination of the OA amount at the unit intake also
involves calculation of a space and system “ventilation efficiency” value per equations in
ASHRAE 62.1-2004/7. This section develops the procedures for system level ventilation
calculations, but there is also considerable discussion involving spaces.
"Critical Space" involves a concept that meeting the ventilation requirements of one space may
require over ventilating other spaces. The example in Figure C-10 supposes space “A”
requires a total of 800 CFM supply air, which includes 200 CFM of outside air, or 25% of
supply. Space "B" requires a total of 600 CFM supply air, which includes 300 CFM of outside
air, or 50% of supply. Both spaces receive supply air from the same RTU. If that RTU total
supply air contains 25% ventilation air, the ventilation requirement of Space “A” are met, but
does not meet the ventilation requirement of Space “B”. The outdoor air fraction defines
ventilation air as a percentage of supply air to the space, the higher the fraction, the more
critical the space tends to be.
Figure C-10 Typical VAV System and Critical Space
OA
SA
The common supply air must contain more than 25% outdoor air in order to meet Space “B”
requirements resulting in over ventilating of Space “A”. However, once Space “A” is over
ventilated, there is unused or "unvitiated" ventilation air that re-circulates from Space “A” which
Energy Simulation for Commercial Buildings
Page ‐ 177 -
[ENERGY SIMULATION]
2015 June 22
moderates the need to increase the ventilation rate to 50% of supply air. In this example, Space
“B” is the critical space, as it requires a greater outdoor air fraction than any other space. The
Critical Space concept existed in ASHRAE 62-2001 but the mathematics for handling it are
different because in Standard 62.1-2004/7 a new term called “ventilation efficiency” is calculated
and taken into account. The Standard defines a complex calculation procedure that HAP follows
to determine the ventilation efficiency for each space. This calculation procedure is different
depending on the system type. A dual duct or recirculation system like fan powered VAV boxes
requires a more involved calculation.
There is a relationship between percent OA for the space and the ventilation efficiency that HAP
takes into account using the equation in ASHRAE 62.1-2004/7. The bottom line is that the
procedure for finding the critical space as defined by ASHRAE 62.1-2004/7, is complex and
system dependent. Both the percent of outdoor air to supply air for the space and the percent of
outdoor air for the system are considered. The larger this difference, the smaller the space
ventilation efficiency and the more likely the space is critical. This difference tends to get larger
when a pace has a higher percent of outdoor air to supply air.
The “critical” space for a system is the one having the lowest ventilation efficiency. For example, if
a space requires 200 CFM of outdoor air and has a ventilation efficiency of 0.75, 200/0.75
requires 267 CFM of outdoor be introduced at the system intake to ensure that the space
receives its 200 CFM of outdoor air. Therefore, the space with the lowest ventilation efficiency
dictates the overall outdoor airflow for the system since it requires the largest amount of over
ventilation of other spaces to ensure it receives its required airflow.
HAP uses the critical “space” ventilation efficiency as the “system” ventilation efficiency thus
enabling the calculation of design ventilation rate for the central system. The Standard refers to
this value as "outdoor air intake." In the HAP Ventilation Sizing Summary Report, this outdoor air
intake is the same as the Design Ventilation Airflow Rate in the case of the VAV system example.
HAP calculates this by dividing the Uncorrected Outdoor Airflow by the System Ventilation
Efficiency.
Note: A dedicated OA system providing 100% outdoor air to all spaces, as shown below, sums
the ventilation values for all spaces in the system and uses that sum as the total system
ventilation airflow. The required air for each space is set at the diffuser and sizes the 100% OA
unit for the sum. There is no “critical space” calculation required.
Figure C-11 No Critical Space Issues with Dedicated OA Unit
Energy Simulation for Commercial Buildings
Page ‐ 178 -
2015 June 22
[ENERGY SIMULATION]
Ventilation Sizing Summary Report
The last section of this discussion uses the preceding information to interpret the output data from
the Ventilation Sizing Summary Report in HAP. The example system is a 7-zone VAV system
supplying multiple classroom spaces, small computer lab, corridor and vestibule using the
ASHRAE 62.1-2004/7 ventilation procedures.
The total cooling coil load for this 7-zone system is 26.4 tons occurring at August 1500 as shown
below. This reflects a Design Ventilation Airflow Rate calculated by HAP based on ASHRAE 62.12004/7 requirements of 2547 CFM. Notice the Design Condition for ventilation air is at the
“minimum flow (heating)”. As discussed previously, because this is a cooling and heating system,
HAP does the Standard 62.1-2004/7 ventilation air calculation once for cooling and once for
heating and uses the higher of the two values. In this example, heating duty was higher because
the heating duty air distribution effectiveness was lower (0.80) than cooling duty (1.0) which
results in 25% more ventilation air requirement to each space during the heating cycle.
Figure C-12 Ventilation Report for VAV System
The following discussion explains the column headings of the Ventilation Sizing Summary Report
for our VAV system. Refer to Figure C-12.
Energy Simulation for Commercial Buildings
Page ‐ 179 -
2015 June 22
[ENERGY SIMULATION]
Minimum Supply Air (CFM)
This value represents the minimum supply airflow (not just the outdoor airflow) for the VAV
terminal for each space. In the HAP Air System Properties under the Zone Components tab/
Supply Terminals/ Minimum Airflow, we defined the minimum supply airflow at 50% of the supply
terminal airflow. Notice in this example the Design Ventilation Airflow is less than the Minimum
Supply Air CFM. HAP automatically increases (overrides) the minimum Zone supply airflow when
the users’ input value for minimum zone airflow does not achieve the minimum required
ventilation.
As an added note, this column heading only appears for VAV. For a CAV system, the column
heading is “Maximum Supply Air (CFM)” because a CAV system diffuser has no minimum airflow
set-point like a VAV terminal.
Floor Area (sq ft)
This is the space floor area used in the uncorrected ventilation airflow calculation based on
CFM/Ft².
Required Outdoor Air (CFM/Ft²)
This represents the part two value for the OA requirement based on Space Usage in ASHRAE
62.1-2004/7.
Time Averaged Occupancy
This value represents the number of occupants used in the final calculations for ventilation air.
HAP accounts for any headcount reductions based on the time averaging factor calculations
discussed earlier.
Required Outdoor Air (CFM/Person)
This represents the part one value for the OA requirement based on Space Usage in ASHRAE
62.1-2004/7.
Air Distribution Effectiveness
This value takes into consideration the ability of the supply air from the diffusers or registers to
reach the breathing zone of its occupants effectively. Our case used 0.80 because heating duty
ventilation airflow (0.80 effectiveness) exceeded cooling duty ventilation airflow (1.0
effectiveness).
Required Outdoor Air (CFM)
This column contains the calculated outdoor air quantities after taking into account the air
distribution effectiveness. The uncorrected outdoor air CFM divided by the air distribution
effectiveness is the required outdoor air CFM for each space. This is not the final airflow for the
common OA intake for the system.
Uncorrected Outdoor Air (CFM)
This column contains the part one and two outdoor air quantities before taking into account the air
distribution effectiveness and critical space issues after considering the time averaging factor for
occupancy.
Energy Simulation for Commercial Buildings
Page ‐ 180 -
2015 June 22
[ENERGY SIMULATION]
Space Ventilation Efficiency
HAP uses space ventilation efficiency in identifying the critical space in the system. The space
with the lowest ventilation efficiency is the most critical therefore it dictates the outdoor airflow for
the system to ensure it receives its required airflow. The Uncorrected Outdoor Air (1760) divided
by the lowest Space Ventilation Efficiency (.691) value is the final answer called Design
Ventilation Airflow Rate (2547).The Space Ventilation Efficiency is calculated by HAP using the
procedures in Appendix A of the Standard, as opposed to using the more simplified method in
table 6-2 of the Standard. This results in the highest level of accuracy.
Conclusion
ASHRAE Standard 62.1-2004/2007 requires HVAC systems to bring in outdoor air at specified
minimum ventilation rates that will be acceptable to human occupants to minimize the potential
for adverse health effects.
Determining the ventilation airflow for each space involves summing a two-part OA requirement
then applying a time averaging factor that adjusts for occupant fluctuation in the space.
Differences exist in the space usage choices between Standard 62-2001 and standard 62.12004/2007.
Next HAP considers the ability of the cooling/heating system to deliver air to the breathing zone
per standard 62.1-2004/2007. The effectiveness value represents the required increase for space
ventilation airflow to compensate for a less effective air delivery.
Then HAP uses ASHRAE 62.1-2004/2007 equations in determining ventilation requirements for
the central system intake to ensure each space receives its required ventilation. This process
involves finding the critical space. The critical space is the one that exhibits the lowest ventilation
efficiency and dictates the overall outdoor airflow for the system.
The purpose of ASHRAE 62.1-2004/2007 is to specify minimum ventilation rates to help achieve
acceptable indoor air quality through constant dilution using outdoor air. ASHRAE considers
these minimums as good design practice for achieving acceptable indoor air quality.
Energy Simulation for Commercial Buildings
Page ‐ 181 -
2015 June 22
[ENERGY SIMULATION]
System Based Design Load Calculations
In HAP, two of the important concepts in design load calculations involve the use of the ASHRAE
heat extraction method and "system-based" sizing techniques. Both are concepts that have been
used since HAP 3.0, but it is useful to review them since it is important to understand the
principles and procedures involved as well as their effects on results. In this article the system
sizing procedures used in HAP will be explained with emphasis on the roles heat extraction
calculations and system-based sizing play.
Definitions. Before beginning, it will be useful to provide brief definitions of heat extraction and
system-based sizing:

Heat Extraction Procedures represent the second part of the two-step ASHRAEendorsed transfer function load method. The first part is the basic transfer function
calculation, which accounts for the transient nature of the processes that convert heat
gains to cooling loads. Heat gains usually do not instantly become cooling loads, but
rather involve a time delay due to heat storage. However, the loads calculated with the
basic transfer function equations are based on the idealized assumption of a constant
room temperature 24 hours per day. Heat extraction procedures are used to take the
calculation one step further considering the effect of varying zone temperatures during the
day (such as set-up or shutdown periods at night) and how air-conditioning systems and
thermostat controls respond to load conditions. The most compelling reason to include
heat extraction in design calculations is that they provide a way to obtain realistic,
accurate estimates of pull-down loads.

System-Based Design considers system specifics when sizing systems. Many load
estimating programs deal with systems in a generic manner. Thermostat set-points,
supply air controls and fan characteristics are specified without being associated with a
specific system control such as variable air volume (VAV) or constant air volume (CAV).
However, different sizing procedures are needed for VAV and CAV. With a generic
approach, it is up to the user to decide how to use program outputs to size a specific type
of system. With HAP, sizing calculations and outputs are tailored to the system type
specified by the user, thus making the results more accurate and easier to use.
Sizing Overview. In HAP, sizing calculations are performed for all system types using the
following three-step procedure:

Size Zone Airflows. Zones are dealt with separately to determine peak sensible loads and
required airflow rates.

Size Supply Fan Airflow. Zone airflow requirements are then combined to determine the
maximum supply fan airflow requirement.

Size Coils. Given user specifications of air system characteristics plus the calculated zone
and fan sizing data, the program simulates operation of the system for design cooling
conditions each month. A simulation is also performed for the design heating condition. Coil
loads resulting from these simulations are inspected to identify the maximum load for each
coil in the system. These are reported on program outputs.
In the paragraphs below, each of these steps are discussed in detail.
Energy Simulation for Commercial Buildings
Page ‐ 182 -
2015 June 22
[ENERGY SIMULATION]
Step 1: Zone Airflow Sizing. The goal of this step is to identify the maximum sensible load and
maximum airflow rate for each zone in the system. To do this the program deals with each zone
separately. Using space and zone input data and ASHRAE transfer function procedures; the
program calculates heat gains for all heat sources in a zone and converts the heat gains to
"cooling loads". Per ASHRAE procedures, these cooling loads are based on the assumption that
cooling equipment operates 24 hours per day and that the zone is maintained exactly at the
cooling thermostat set-point. Thus, these cooling loads are idealized unless the system will
actually operate this way. This simplifying assumption will be compensated for later during the
coil simulations using the heat extraction procedure.
After calculating loads for all design cooling months specified, the program searches the data to
identify the maximum zone sensible cooling load. For a given supply air temperature, the program
calculates the required airflow rate to satisfy this load.
Results of the zone airflow sizing analysis appear on the Zone Sizing Summary report. Zone
sensible loads from this analysis also appear on the Air System Design Load Summary, Zone
Design Load Summary and Hourly Zone Design Day Loads reports. On these reports, the cooling
loads are interchangeably referred to as "zone load" and "zone sensible.”
Step 2: Fan Airflow Sizing. The goal of this sizing step is to determine the maximum airflow
requirement for the central supply fan. This is the first calculation in which system-based sizing is
involved. For a CAV system, the program adds peak CFMs (L/s) for all zones to determine the
required supply fan airflow. For VAV systems, the program identifies the peak coincident CFM
(L/s). This is done by first using zone sensible load data from the previous step to determine
require airflow rates for each hour of the day. Hourly airflow requirements for each zone are then
added together to build a fan airflow profile. Finally, the program searches this profile to find the
maximum airflow rate.
Figure D-1 VAV System Airflow Rates
Energy Simulation for Commercial Buildings
Page ‐ 183 -
2015 June 22
[ENERGY SIMULATION]
Figure D-1 illustrates this calculation for a VAV system. Zone airflow rates are shown in this figure
for an east-facing zone and a west-facing zone. For each hour, the sum of east and west zone
airflow rates is the required fan airflow rate. In Figure 1, the east zone peaks at 0900 with a 6252
CFM (2950 L/s) requirement, the west zone peaks at 1700 with a 6989 CFM (3298 L/s)
requirement, and the supply fan peaks at 1600 with a 10213 CFM (4820 L/s) requirement. Note
that this VAV fan airflow is 23% less than the 13241 CFM (6248 L/s) that would be required for a
CAV system. Because a VAV system can take advantage of load diversity, its design airflow can
often be less than the sum of peak zone CFMs (L/s). When a VAV air system is specified in HAP,
the system-based sizing procedure automatically considers this.
Step 3: Coil Sizing Calculations. The goal of the final sizing step is to determine maximum
loads for all coils in the air system. Performing detailed simulations of air system operation for
each design cooling month and the design heating condition does this. Air system input data, the
airflow rates and zone sensible load profiles calculated in steps 1 and 2, and ASHRAE heat
extraction procedures are used to perform these simulations. Simulations are specific to the type
of system being dealt with and consider all system components and controls specified.
The zone sensible load profiles calculated in step 1 are the basis for system simulations. As
noted earlier, these load profiles were calculated assuming 24-hour equipment operation and a
constant zone temperature equal to the occupied cooling thermostat set-point. Consequently,
these load profiles must be adjusted using the ASHRAE heat extraction equations if cooling
equipment is operated for less than 24 hours, if an unoccupied period set-up temperature is used,
if cooling equipment is shut down during the unoccupied period and if a thermostat throttling
range other than 0º F (-17.8º C) is used. The heat extraction calculations yield the amount of heat
the air conditioning system must remove each hour to maintain the zone in the thermostat
throttling range. Once zone heat extraction rates have been computed, this data serves as the
basis for calculations of airflow rates, temperatures and humidity at all points in the air system.
Finally, these results allow loads for coils in the system to be determined. For example, the
cooling coil inlet and outlet dry-bulb temperatures and the coil airflow rate are used to calculate
the sensible coil load.
Figure D-2 provides sample results from a design simulation for a single-zone CAV air system.
The figure provides a useful comparison between zone sensible loads, heat extraction rates
(called "zone conditioning") and sensible and total cooling coil loads.
The "zone sensible" load profile represents sensible cooling loads assuming 24-hour equipment
operation and a constant 75º F (23.9º C) zone air temperature. The "zone conditioning" profile
represents heat extracted from the zone during the 6am-7pm operating period (from 8pm to 5am
the cooling system is off). During this operating cycle, the zone air temperature varies within in
the 75º F (23.9º C) - 78º F (25.5º C) throttling range during the 6am-7pm operating period, and
floats at higher temperatures during the nighttime shutdown period. Heat extraction method
estimates of zone air temperature are shown in Figure D-3. As a result of this behavior, extra load
is imposed on the air conditioning equipment to pull down the zone air temperature and to
remove heat that has accumulated in the building mass during the nighttime period. This pulldown load is the principal reason for differences between the zone sensible and zone
conditioning profiles in Figure D-2. Note that these differences are most significant at the start of
the operating period, but also continue throughout the 13-hour operating period.
The coil sensible profile in Figure D-2 represents the sensible heat that must be removed at the
central cooling coil. In addition to providing enough sensible cooling to meet zone-conditioning
demands, the coil must also provide cooling to offset fan heat gain, sensible ventilation load and
the portion of plenum heat gains that returns to the coil. These factors cause the coil sensible
profile in Figure D-2 to exceed than the zone conditioning profile for all hours. Finally, the total coil
load profile in Figure D-2 represents total heat removal at the cooling coil. The difference between
the total and sensible coil profiles is the latent cooling provided by the coil.
Energy Simulation for Commercial Buildings
Page ‐ 184 -
2015 June 22
[ENERGY SIMULATION]
Figure D-2 Zone and Coil Load Profiles
Results from the coil sizing analysis are reported on the Air System Sizing Summary. Zone
conditioning and coil load data are also provided on the Air System Design Load Summary and
Hourly Air System Design Day Loads reports. Zone temperatures and zone conditioning are listed
on Hourly Zone Design Day Loads reports.
Implication: Performance-Based Coil Estimate. While it is useful to understand the sizing
procedures used in HAP, it is even more important to recognize the implications of the
procedures. The most significant of these is that the system simulation technique used yields a
"performance-based" estimate of peak coil loads. By this, we mean that the calculation considers
all system controls and operating variables. Perhaps most important among these is the variation
of zone temperature.
As noted earlier, zone temperature will vary during the unoccupied set-up or shutdown period,
and within the thermostat throttling range during the occupied period. In Figure D-3, for example,
zone temperatures lie toward the upper end of the 3º F (-16.1ºC) thermostat throttling range
during the 13-hour occupied operating period. This is not necessarily always the case. If
unoccupied cooling at a set-up temperature was provided, or 24-hour cooling was provided, the
pull-down load component would be less severe or eliminated altogether and zone temperatures
would tend to lie closer to the bottom of the throttling range.
These temperature variations may or may not be desired by the designer. On one hand, some
designers wish to consider actual operating characteristics in the calculation, including zone
Energy Simulation for Commercial Buildings
Page ‐ 185 -
2015 June 22
[ENERGY SIMULATION]
temperature variations, and are therefore comfortable with a performance-based calculation.
Others may want to use idealized conditions with the zone temperature fixed exactly at a single
set-point temperature.
Figure D-3 Zone Air Temperature Profile
Energy Simulation for Commercial Buildings
Page ‐ 186 -
[ENERGY SIMULATION]
2015 June 22
Figure D-4 Loads for Varied Throttling Ranges
Figure D-5 Zone Temperatures for Varied Throttling Ranges
Energy Simulation for Commercial Buildings
Page ‐ 187 -
2015 June 22
[ENERGY SIMULATION]
While the performance-based nature of the coil simulations cannot be eliminated completely,
using a throttling range of 0.1ºF (-17.7ºC) can minimize it. Note that a finite throttling range is
required by the heat extraction method. Without it, the analysis cannot be performed and pulldown loads cannot be computed; 0.1ºF (-17.7ºC) is the minimum allowed by the program. Using
this throttling range will have an effect both on the zone conditioning and cooling coil loads
calculated, as well as the estimates of zone temperatures. Results from the single-zone CAV
example for both 3 F (-16.1ºC) and 0.1ºF (-17.7ºC) throttling ranges are shown in Figures D-4
and D-5. Use of the 0.1ºF (-17.7ºC) throttling range results in a peak cooling coil load that is 4%
larger than the 3ºF (-16.1ºC) throttling range case. It also results in estimated zone temperatures
closer to the 75ºF (23.9ºC) cooling set-point as shown in Figure D-5.
Thus, system based design using the heat extraction method offers powerful, sophisticated
capabilities to user. But to successfully use the heat extraction method, a designer must
understand the procedure and its implications.
Energy Simulation for Commercial Buildings
Page ‐ 188 -
2015 June 22
[ENERGY SIMULATION]
Appendix “C”
Technical White Papers
Energy Simulation for Commercial Buildings
Page ‐ 189 -
2015 June 22
[ENERGY SIMULATION]
Introduction
In 1993 Carrier incorporated system-based design features in its Hourly Analysis Program
(HAP) software. At the time, system-based design was a new concept that allowed the computer
to do a more complete and accurate job of sizing equipment than the traditional load estimating
approach. Ten years later, this approach still yields significant benefits to HVAC system
designers because of the productivity advantage it offers. And even today it still serves to
differentiate HAP from other load estimating and system design software on the market.
This paper explains system-based design and its benefits. First the paper discusses how
traditional system design methods work and the shortcomings of the traditional approach. Next,
the concept of system-based design is explained, and the benefits it offers are explored.
How Traditional System Design Methods Work
Many computer programs used for HVAC system design are based on a traditional approach that
manual methods use. First, the engineer inputs weather data, information about the building
construction, internal loads and layout, and HVAC sizing parameters. The latter includes such
things as thermostat set-points, the required supply temperature and the required outdoor air
ventilation rate. Using this data the program then:

Computes zone sensible cooling loads for all zones for a series of design cooling months.

Identifies the maximum zone sensible load for each zone in order to calculate required zone
airflow rates and the required supply fan airflow rate.

Calculates central cooling coil loads for the months being considered in order to identify the
maximum cooling coil load.

If the system also provides heating, calculations are performed to determine the maximum
heating coil load.
This procedure yields data useful for sizing terminal diffusers, the supply fan, the central cooling
coil, and the central heating coil.
Shortcomings of the Traditional Approach
It is important to note the traditional approach does not explicitly consider the type of HVAC
system being designed. This approach is acceptable when designing simple CAV or VAV
systems. However, when an HVAC system with special features, components or aspects of
operation is involved, the traditional approach has two important flaws.
First, it leaves a gap between what the engineer needs to design the system fully, and what the
program provides as sizing data. Different types of HVAC systems contain different components
which each need to be sized. Further, different types of HVAC systems require different sizing
procedures. Therefore defining the system type is necessary to determine the components to be
sized and the procedures to be used. The following examples illustrate this point:

A single zone CAV system requires that the supply diffusers, supply fan and the central
cooling and heating coils be sized. The supply fan airflow is equal to the required airflow for
the single zone.

A VAV Reheat system serving multiple zones requires that supply diffusers, the supply fan,
the central cooling coil and the terminal reheat coils be sized. The supply fan is sized for the
Energy Simulation for Commercial Buildings
Page ‐ 190 -
2015 June 22
[ENERGY SIMULATION]
diversified peak airflow to zones, rather than the sum of zone airflows. The terminal reheat
coils are sized using a procedure that is different from sizing a central heating coil.

A VAV Fan Powered Mixing Box system serving multiple zones requires that supply diffusers,
mixing box terminals, the supply fan and the central cooling coil be sized. Unlike other
systems, the terminal equipment for this system includes both a fan and a reheat coil, both of
which must be sized. Sizing procedures differ slightly depending on whether a series mixing
box or parallel mixing box terminal is used.

A 2-Fan Dual Duct VAV system serving multiple zones requires that supply diffusers, mixing
box terminals, the cold deck supply fan, the hot deck supply fan, the cold deck cooling coil
and the hot deck heating coil all be sized. This system contains a unique configuration of
components not found in other systems. Procedures tailored to this type of system must be
used to properly size the equipment.
The second problem with the traditional approach involves accuracy. If the traditional approach is
used to size a system such as series Fan-Powered Mixing Box or 2-Fan Dual Duct, additional
hand calculations will be required to size components not addressed by the calculation. These
additional hand calculations make the design more difficult, more time consuming and prone to
error. In more complex situations, sizing is often approximated to save time. Thus, the traditional
approach plus hand calculations is often less accurate than a computerized approach that
considers system type and does a complete job.
System-Based Design and How It Works
The system-based design approach considers the unique features of the HVAC system being
designed and then tailors the load estimating and sizing procedures to that system. It can
therefore provide specific, accurate sizing information for each component of the system.
If a Series Fan Powered Mixing Box system is being designed, for example, the system-based
approach will provide the information necessary to size the terminal mixing boxes, their fans and
heating coils. It will also consider the special operating features of the system to determine
accurate primary supply fan and primary cooling coil sizes. In this way sizing methods and output
data are customized to each specific system type.
By providing system-specific sizing data, the system-based design approach can bridge the gap
between what an engineer needs and what a computerized system design program provides.
How It Works. The information a designer must supply to initiate the design process is similar to
the traditional approach. The engineer must:

Input weather data.

Input building construction, internal heat gain and layout information.

Define the HVAC system. In addition to thermostat set-points and sizing criteria, the engineer
specifies exactly what type of HVAC system is involved and its attributes. For example, it
could be VAV Reheat, VAV with baseboard heat, Series Fan Powered Mixing Box, Dual Duct
VAV, etc...
Next, the system-based design computer program calculates loads and sizes system
components:
Energy Simulation for Commercial Buildings
Page ‐ 191 -
2015 June 22
[ENERGY SIMULATION]
1. Zone Load Calculation. The program first calculates hourly zone sensible cooling loads for
all zones for the design cooling months being considered.
2. Zone Airflow Sizing. The program then identifies maximum zone sensible loads in order to
determine required zone supply airflow rates and required central fan airflow rates. For some
systems, such as fan powered mixing box systems, special aspects of system operation may
influence the required airflow rates.
3. System Simulation. Once system airflows have been determined, the program simulates the
hour-by-hour operation of the HVAC system and all its components to determine loads for all
coils in the system. This mathematical simulation considers the interplay of component
operation for the specific system being studied. Simulations are performed for the range of
design cooling months specified by the designer and for the heating design condition.
4. Coil Sizing. Finally, the program searches results of system simulation to determine
maximum required size for each component coil in the system.
Benefits of System-Based Design
The major benefit of the system-based design approach, of course, is that it gives the engineer
exactly what is needed to design a system. Specific sizing data is provided instead of raw
material for further hand calculations. The result is increased productivity for the designer
because the computer is being put to work more effectively. The computer does a complete job of
system sizing, not a partial job.
A related benefit is that the system-based approach does a more accurate and therefore reliable
job of generating sizing data. This is because sizing calculations consider the specific operating
nature of the system, not the features of a simple, generic system. Further, the approach can
evaluate more operating conditions than can be checked by hand, so that the approach is more
thorough and comprehensive.
Finally, because detailed, dynamic system simulations are part of this approach, the method can
potentially be used to investigate the effect on sizing of such devices and controls as:

Outdoor air ventilation energy recovery devices.

Outdoor air economizers.

Active dehumidification and humidification controls.

Night-time free cooling controls.
Previously, such controls have only been evaluated in energy analysis simulations to determine
effects on operating costs. But each can also have an effect on sizing which in turn can have a
significant effect the first cost of the system.
Conclusion
Even though the concept is no longer brand new, system-based design still represents a
promising advance in the field of HVAC system design. It offers improvements in productivity and
accuracy, and opens new avenues of investigation to the designer in the pursuit of the optimal
design. Look for it when choosing your HVAC design tools.
Energy Simulation for Commercial Buildings
Page ‐ 192 -
[ENERGY SIMULATION]
The Benefits of 8760 Hour by Hour Building Energy Analysis
Introduction
As energy costs rise, building owners are becoming increasingly interested in operating costs and
energy efficiency. As a result, building energy analysis (BEA) is becoming an important tool in the
HVAC design field. Currently many BEA tools are available to engineers. Most are in the form of
computer programs and employ a variety of methods with different benefits. Among these, BEA
tools such as Carrier's HAP program that use the 8760 hour-by-hour method can offer the
greatest benefits because they yield highly accurate, sophisticated system comparisons. This
article will discuss the benefits of 8760 hour building energy analysis by first explaining the basics
of building energy analysis and the requirements for high quality BEA system comparisons. Then,
major BEA methods will be evaluated with special emphasis on the benefits of 8760 hour-by-hour
versus reduced hour-by-hour methods.
What Is Building Energy Analysis?
Building energy analysis is the technique of estimating energy use and operating costs for a
building and its energy consuming systems. In our industry, particular emphasis is placed on the
energy use of a building's HVAC systems. The purpose of BEA is to compare the energy use and
operating costs of alternate system designs in order to choose the optimal design. The analysis
mathematically simulates the thermal performance of the building to determine cooling and
heating loads. It then mathematically simulates the performance of HVAC equipment in response
to these loads to determine energy use over the course of a year. Finally, energy data is used to
calculate operating costs.
Requirements for High Quality Results.
Successful building energy analysis relies on considering as many of the physical factors
influencing building loads and equipment performance as possible. The ultimate result of the
analysis is a predicted operating cost. An accurate cost prediction relies on energy use data,
which in turn relies on equipment simulations, which must be based on building load predictions,
all of which must be accurate. Concisely stated, high quality results can be obtained when the
analysis considers:
1. The Range and Timing of Weather Conditions. Varying levels of temperature, humidity
and solar radiation during the year influence building loads and equipment performance. In
each geographical location conditions range from hot to cold, wet to dry and sunny to cloudy
in different ways. Considering the actual ranges of these conditions and when they occur on a
daily, monthly and yearly basis is crucial to producing accurate energy use results.
2. The Hourly and Daily Variation in Internal Loads. Patterns of building use involving
occupancy, lighting and equipment operation can change significantly from one day to the
next. Considering these use patterns in their correct day-to-day sequence is important in
generating accurate load data.
3. The Dynamic Nature of Building Heat Transfer. The process of converting heat gains and
losses to cooling and heating loads is a transient rather than a steady-state process. Heat
gains occurring during one hour often affect loads over a number of succeeding hours.
Consequently, it is important to consider accurate sequences of heat gains occurring during
the day. In addition, because weather conditions and building use profiles vary from day to
day, sequences of heat gains can affect loads from one day to the next.
Energy Simulation for Commercial Buildings
Page ‐ 193 -
2015 June 22
[ENERGY SIMULATION]
4. The Response and Performance of HVAC Equipment. How controls, systems and
equipment respond to demands for cooling and heating in a building, and the factors that
affect part-load performance of the equipment must be considered to yield accurate
equipment energy use data.
5. The Details Of How Utilities Charge For Energy Use. Often prices for energy vary by
season and time of day. Further, charges are often made for peak energy usage. As a result,
the analysis must not only be able to produce accurate estimates of how much energy is
used, but must also accurately determine when during the day energy is used.
Evaluation of BEA Methods
A wide variety of building energy analysis methods are currently available to HVAC engineers
and range from simple to sophisticated. The simplest methods involve the largest number of
simplifying assumptions and therefore tend to be the least accurate. The most sophisticated
methods involve the fewest assumptions and thus can provide the most accurate results.
Generally, BEA methods are divided into three categories:
a) Single Measure Methods (example: Equivalent Full Load Hours)
b) Simplified Multiple Measure Methods (example: Bin Method)
c) Detailed Multiple Measure Method (example: Hour by Hour)
While methods in the first two categories serve a useful role in providing quick, preliminary energy
estimates, the simplifications they involve impair their accuracy. Each will be briefly discussed
below. The main focus of the following discussions, however, will be the different hour by hour
methods contained in the third category.
Single Measure Methods
These methods involve one calculation of annual or seasonal energy use. The Degree-Day
Method, for example, computes energy use by combining one degree-day weather value with a
load value and an efficiency value to obtain seasonal or annual energy use. Similarly, the
Equivalent Full Load Hour Method combines full load capacity, full load efficiency and equivalent
full load hours to obtain annual energy use. In both cases, this level of simplicity is achieved by
using such sweeping assumptions that the accuracy and reliability of these methods are very
limited.
Simplified Multiple Measure Methods
These methods involve calculations of energy use at several different conditions. With the Bin
Method, for example, energy use is computed at a series of outdoor air dry-bulb conditions.
Results are then weighted according to the number of hours each dry-bulb condition is expected
to occur to determine annual energy use.
For example, the temperature 47ºF would be used to represent the range of conditions between
45ºF and 50ºF, referred to as a "bin". Building loads and equipment energy use would first be
calculated for the 47ºF bin. Next, energy results would be multiplied the number of hours per year
temperatures are expected to occur between 45ºF and 50ºF to determine annual energy use for
that bin. Similar calculations would then be repeated for all other temperature bins for the local
climate and would be summed to determine overall annual energy use.
While the Bin Method provides a vast improvement in sophistication over single measure
methods, it has a fatal flaw. This flaw is that it must decouple weather conditions, loads and
system operation from time. For example, hours in the 47ºF bin, when the outdoor dry-bulb is
Energy Simulation for Commercial Buildings
Page ‐ 194 -
2015 June 22
[ENERGY SIMULATION]
between 45ºF and 50ºF, occur at a variety of times of day and night, days of the week and
months of the year. Because a single calculation is performed to represent energy use for all
these different times it is difficult or even impossible to accurately:
a)
b)
c)
d)
Link solar radiation and humidity conditions to the bin.
Consider hourly and daily variations in internal loads.
Consider the transient hour to hour and day to day thermal performance of the building.
Predict time-of-day energy use and peak demands.
Inevitably averaging assumptions must be made to shoehorn all these considerations into the
framework of the bin analysis. And these assumptions impair accuracy. While the Bin Method is
useful for simple, preliminary estimates of energy use and operating cost, it cannot provide the
level of accuracy and sophistication offered by the detailed multiple measure methods.
Detailed Multiple Measure Methods
These methods perform energy calculations on an hour-by-hour basis. As a result, they have the
potential to satisfy all the requirements listed earlier for high quality energy analysis results. There
is, however, a certain amount of variation among different detailed multiple measure methods,
leading some methods to meet the accuracy requirements better than others. Within the detailed
multiple measure category are two major sub-categories worth discussing:
a) The Reduced Hour-By-Hour Method
b) The 8760 Hour-By-Hour Method.
Reduced Hour-By-Hour Method: How & Why?
This method typically uses one 24-hour profile of average weather conditions per month. Energy
simulations are performed for this average profile and results are then multiplied by the number of
days in the month to obtain monthly energy totals. Upon this basic foundation, different reduced
hour-by-hour methods make various improvements to enhance the accuracy of results:
a) Some methods analyze building operation for a typical Weekday, Saturday and Sunday each
month since building use profiles differ significantly between these days. One average
weather profile is still used for all three typical day simulations each month.
b) Some methods also analyze equipment operation for a hot and cold day each month in an
attempt to improve estimates of peak electrical demand.
c) Some methods simulate building operation for one 7-day week each month to try to account
for day-to-day building dynamics. However, a one average weather profile is still used for all 7
days of the simulation.
The fundamental principle of this method is that building and equipment performance on hotter
and colder than normal days each month averages out so that monthly energy use can be
accurately predicted by simulating a small group of days using average weather conditions. The
method offers the benefits of reduced calculation time and more moderate demands on computer
memory and hard disk storage space.
Energy Simulation for Commercial Buildings
Page ‐ 195 -
2015 June 22
[ENERGY SIMULATION]
8760 Hour-By-Hour Method: How and Why?
This method simulates building and equipment performance for all 8,760 hours in the year using
the proper sequence of days and actual weather data. No weighting of results or simplifications
are necessary.
The fundamental principle is that the way to produce the most accurate energy and operating
cost estimates is to mimic the real-time operating experience of a building over the course of a
year. All the requirements listed earlier for high quality energy analysis results can be met with
this approach. The actual weather data accounts for the range and timing of weather conditions in
great detail. Further, the hourly and daily variation of building occupancy, lighting and equipment
use can be easily accounted for. In addition, the full year simulation tracks the dynamic hour-tohour and day-to-day thermal behavior of the building, and the response of HVAC equipment to
this behavior. The ultimate result is high-quality data that can be utilized to produce accurate,
detailed data about the quantity and timing of energy use. Both are requirements for accurate
operating cost estimates.
Comparison of Reduced and 8760 Hour-By-Hour Methods
While the Reduced Hour-By-Hour method often provides accurate results, the 8760 Hour-ByHour method can consistently provide superior accuracy and reliability. Among the reasons why,
five stand out:
1. Better Estimates of Monthly Energy Use.
One of the flaws in the fundamental principle of the reduced hour-by-hour method is that it relies
on building and HVAC system behavior being "continuous" and "linear" during the month. Often
these requirements are not met and this adversely affects accuracy
"Continuous" is a mathematical term that in this context refers to a consistent mode of operation
(it does not refer to constant 24-hour operation of equipment). For example, during a summer
month HVAC system operation is continuous when cooling is consistently done on all days
whether hot, cool or average weather conditions prevail. In this situation simulation of system
performance for one 24-hour average weather profile has the best chance of approximating the
total energy use for a month.
However, system operation is often not "continuous" during a month, especially during
intermediate seasons. For example, during an autumn month, cooling may be done on warmer
than average days, economizer operation may occur on average days, and heating may occur on
cooler than normal days. A simulation of one average day for such a month may indicate little or
no cooling and heating because it does not consider the warmer and colder than average
conditions.
In moderate climates this problem can become severe when the only time heating occurs is on
colder than average winter days. Because only average winter weather is considered, most or all
of the heating duty for the year may be missed by an average-day simulation approach.
Finally, "linear" behavior is a requirement for averaging to be accurate. For example, if cooling
loads are 20% larger when the temperature is 15ºF warmer than average, and 20% smaller when
the temperature is 15ºF cooler than average, cooling loads are linearly proportional to outdoor
temperature. Averaging of the warm day and cool day loads will result in loads similar to those
produced by simulating only the average weather day. However, loads depend on more than just
outdoor temperature. Solar radiation, internal loads and hour-to-hour and day-to-day dynamic
behavior also affect loads and often result in non-linear behavior.
Energy Simulation for Commercial Buildings
Page ‐ 196 -
2015 June 22
[ENERGY SIMULATION]
Another example involves cooling equipment. If equipment input kW decreases 8% for every 10%
drop in part-load ratio, input kW and load are linearly proportional. If this relationship holds true,
simulation of equipment performance for one average day per month has the best chance of
accurately approximating equipment performance on the collection of hot, average and cool days
during the month. Unfortunately, the performance of equipment is often non-linear due to partload, entering condenser temperature and other performance factors. Consequently, the
accuracy of the average day approach can be degraded when equipment behavior is non-linear.
The 8760-hour method avoids these problems by simulating building and equipment operation for
the entire month. Actual weather data used by the simulation consists of a collection of days, all
with different combinations of temperature, humidity and sunshine.
Figures E-1 and E-2 provide an example of this kind of data for the month of September in
Chicago. Figure E-1 demonstrates the way dry-bulb temperatures can vary during a month. The
dotted lines in this figure are the upper and lower limits of the average temperature profile for the
month that would be used by the reduced hour-by-hour method. Comparison of the average and
actual data shows a significant number of hours outside the range of conditions considered by the
average day simulation approach.
Figure E-1 Chicago Weather/September Dry Bulbs
Figure E-2 Chicago Weather/September Solar
Likewise, Figure E-2 demonstrates the variation of solar radiation profiles during the month. The
dotted line indicates the maximum solar flux in the average day profile used by the reduced hourby-hour method. Once again, there are many conditions with greater sunshine and less sunshine
than considered by the average day approach. More importantly, comparison of the peaks and
Energy Simulation for Commercial Buildings
Page ‐ 197 -
2015 June 22
[ENERGY SIMULATION]
valleys in Figures E-1 and E-2 shows that hot days are not always sunny, and cool days are not
always cloudy. The diverse collection of hot, cold, sunny, cloudy and in between conditions
shown in these figures illustrates the complex nature of actual weather data and provides
evidence that building loads will not be a simple linear function of outdoor air temperature.
By considering a diverse collection of weather conditions each month, the 8760 hour method
produces a diverse, realistic set of cooling and heating loads for the month. Further, because a
full month of days are simulated, the appropriate factors influencing equipment performance are
considered. There is no reliance on the assumption of "continuous" or "linear" behavior, and the
estimates of monthly energy use can be highly accurate.
2. Higher Quality System Comparisons.
The issues discussed under item (1) affect not only the accuracy of monthly energy estimates, but
also the quality of system comparisons. This is because many of the system design alternatives
commonly considered exhibit behavior that is both discontinuous and non-linear.
"Discontinuous" refers to inconsistent operation. That is, operation that starts and stops rather
than continuing for all operating conditions during a month. "Non-linear" refers to the fact that
there is often not a simple proportional relationship between load or outdoor temperature and
equipment performance, as discussed in item (1).
A comparison of air handling systems with and without a non-integrated outdoor air economizer
provides a good illustration of this problem. With this type of economizer control, economizer
dampers open when outdoor air temperature drops below the supply air temperature. The system
can then immediately use outdoor air for free cooling; mechanical cooling can be turned off. For
this example, assume the supply air temperature is 57ºF and that we are simulating system
operation for the weather data shown in Figure E-1. The dotted lines in this figure indicate the
upper and lower limits of an average temperature profile for the month. Because this average
profile ranges between 58ºF and 75ºF, a simulation using the reduced hour-by-hour approach
would never find a condition when the economizer dampers opened during September; free
cooling would never be available. However, with the 8760 hour method, the use of actual
temperature profiles for the month result in 119 hours during 13 days when temperatures drop
below 57ºF. If cooling loads exist during these times, the economizer would operate to provide
free cooling. Therefore, because an economizer exhibits discontinuous operation, turning on and
off at specific conditions, the reduced hour-by-hour approach may not successfully account for
this operation. In our example the reduced hour-by-hour method would underestimate the benefit
of the economizer.
Similar situations can exist for other system components and controls that involve discontinuous,
on/off behavior. Examples include ventilation heat reclaim, supply air reset, humidity control,
cooling tower fan cycling, and loading and unloading of chiller networks as well as many others.
3. More Accurate Load Histories.
The fact that the 8760 hour method simulates building thermal performance day to day for the
entire year means it can correctly account for day to day dynamic load behavior. This results in
more accurate load profiles, which ultimately lead to more accurate energy use predictions.
For example, on a Monday morning in the summer, pull-down loads tend to be larger than on
other days of the week due to the heat accumulated by the building mass during the weekend. In
addition to resulting in larger cooling loads, these conditions can sometimes set the monthly
electric demand.
Energy Simulation for Commercial Buildings
Page ‐ 198 -
2015 June 22
[ENERGY SIMULATION]
In reduced hour-by-hour methods that do not simulate a full week of operation, each day is
simulated separately from all other days. Consequently, day to day building dynamics cannot be
considered, and the building load histories are more simplistic. In those reduced hour-by-hour
methods that do simulate a 7-day sequence each month, results tend to be unrealistic since the
same average weather profile is used for all 7 days.
4. Higher Quality Time of Use Energy Data.
Because of the diverse weather conditions and operating conditions, and because of the dynamic
nature of building heat transfer, 8760 hour methods can produce energy use data that not only
accurately defines how much energy is used, but when during the day and week the energy is
used. When energy prices vary with time of day, accuracy of the timing of energy use is critical for
producing accurate operating cost data.
5. More Accurate Estimates of Peak Demand.
Finally, by considering the full range of weather and operating conditions experienced by a
building during a month, the 8760 hour method is able to produce more accurate estimates of
peak energy demand. When utility rates include a demand charge component, a significant part
of the energy cost can be due to the peak energy use rather than the quantity of energy used.
Many reduced hour-by-hour methods must determine demands from average day simulations
which tend to underestimate demand values. Those methods that add consideration of hot and
cold day weather profiles can provide an improvement in demand estimates. However, it is
important to recognize that demand will be dependent on more than just the outdoor air
temperature. Solar radiation, internal loads, building use profiles and day to day building
dynamics also play an important role. The 8760-hour method is the only method that can
simultaneously consider all these factors.
Thus, while the Reduced Hour-By-Hour Method considers many of the factors required for highquality energy estimates, certain aspects of the method are flawed and can limit the accuracy of
the method. Because the 8760 hour method uses a more detailed, comprehensive approach to
building simulation, it can consistently overcome these problems to provide accurate, reliable
energy estimates.
Conclusion
This article has discussed the important benefits of the 8760 hour-by-hour building energy
analysis method. This method is certainly not new. Computer programs using this method have
been available for nearly three decades. However, because many of these programs were
developed on mainframe computers as research tools, the programs, and by association, the
8760 hour method itself acquired a reputation of being complicated, difficult and impractical to
use. It is important to note that these are problems with the implementation of the 8760 hour
method, not with the method itself. If the 8760 hour method is implemented in a well-designed,
well-documented microcomputer program, the 8760 hour method can be as easy to learn and
use as reduced hour-by-hour methods. In developing Carrier's Hourly Analysis Program we have
put two decades worth of experience in the HVAC software field to work to produce an 8760 hour
energy analysis tool that is both powerful and easy to use. The resulting program maximizes the
benefits of the 8760 hour method while minimizing or even eliminating costs traditionally
associated with use of this method.
Energy Simulation for Commercial Buildings
Page ‐ 199 -
[ENERGY SIMULATION]
2015 June 22
Carrier Corporation
Carrier University
Bynum Training Center
6540 Old Collamer Rd. S.
East Syracuse, NY 13057
Singapore June 2015 Energy Simulation for Commercial Buildings_HAP4.9_Rev0.00
Energy Simulation for Commercial Buildings
Page 200