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Webinar: The Basics and
Benefits of Commissioning
Erik Jeannette, PE
Architectural Energy Corporation
Boulder, Colorado
www.archenergy.com
© Architectural Energy Corporation
Who am I?
• Erik Jeannette, P.E.
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Controls and building energy efficiency expert
ASHRAE controls research
Controls engineer with Comfort Systems USA
Business Team Leader and Commissioning
Engineer - Architectural Energy Corporation
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: Commissioning
Section 3: Retro-commissioning
Section 4: Case Studies
Section 5: Costs and Benefits
Section 6: Resources
© Architectural Energy Corporation
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Commissioning Definition
• Commissioning is a systematic process
of ensuring that all building or facility
systems perform in accordance with the
design documentation and intent, and in
accordance with the owner’s operational
needs.
© Architectural Energy Corporation
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Commissioning Definitions
• Commissioning:
– Process applied to new construction or major
building renovation
• Retro-commissioning:
– Performed on facilities that have been in service
and never commissioned
• Re-commissioning:
– Facility has previously been commissioned and
is in need of a “tune-up”
• Continuous commissioning:
– On-going program of structured commissioning
throughout the lifetime of a building
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: Commissioning
Section 3: Retro-commissioning
Section 4: Case Studies
Section 5: Costs and Benefits
Section 6: Resources
© Architectural Energy Corporation
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Commissioning for New Construction
• Typical Commissioning Team Members
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Commissioning Provider (CX Agent)
Owner’s Representative (PM)
Architect and Design Engineers (A/E)
General Contractor (GC)
Mechanical Sub-contractor (MC)
Electrical Sub-contractor (MC)
Specialty Sub-contractors (Controls, TAB, Security,
Elevator, etc.)
– Operations and Maintenance Staff
– Equipment Suppliers
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Commissioning Process
Design
Phase
Design Intent,
CX Plan,
Specifications
Review submittals,
Prepare checklists
and
Testing Plans
© Architectural Energy Corporation
Construction
Phase
Verify
Installation,
Start-Up
and
Component
Testing
Acceptance
Phase
Functional
Testing,
Resolve
Deficiencies,
Review
O&M
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Warranty
Phase
Diagnostic
Monitoring,
CX Report,
O+M Staff
Training,
Seasonal
Testing
Commissioning Goals
• All systems working as intended to achieve:
– Occupant satisfaction and safety
• All building systems performing reliably and
safely
• Improved comfort and indoor air quality
– Cost savings
• Energy, equipment maintenance, and equipment
replacement
– Smoother construction process
• Avoided construction problems, quicker final
acceptance, and reduced warranty callbacks
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Commissioning Objectives
• Ensure the facility meets performance
requirements
• Provide a safe and healthy environment
• Provide optimum energy performance
• Provide a facility that can be efficiently
operated and maintained
• Provide complete orientation and training
to facility staff
• Provide improved documentation of
building systems
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What should be Commissioned?
• Whole-building commissioning
– all major building systems: HVAC, electrical,
controls, security, life safety, envelope,
communications, movement, process equipment,
etc.
• Targeted systems
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HVAC equipment, controls
Lighting controls
- Electrical
Building envelope
- Security, Life Safety
Kitchen Equipment
- Plumbing, Irrigation
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Design Phase Commissioning
• Early intervention is better than later
– Every building is a prototype
– Every project will have design and construction
issues
– It will always cost less to fix a problem during
design then during construction or occupancy
– The more eyes on the job, the better
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Design Phase Commissioning
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The cost versus potential impact ratio of the commissioning
effort can be expressed as the “X” Factor:
Design Phase
Construction Phase
Acceptance Phase
Impact
Potential
A
C
B
Commissioning
Cost/Impact
Low Cost
High Impact
© Architectural Energy Corporation
Cost vs. Impact
High Cost
Equal
Low Impact
Construction Phase Commissioning
• Job-Site Observation
– Job-site visits to check installation practices and
catch problems early
– During early system construction, repeated
mistakes can be identified and corrected before they
become widespread
– Digital photos help to track progress and can be
sent to design team for immediate response to items
in question
© Architectural Energy Corporation
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Construction Phase Commissioning
• Equipment Start-Up
– Document completion of and adherence to
manufacturer’s start-up recommendations
– Typically asking contractors to document what
they already do
– Provide engineering expertise during start-up
– Aid in integrating vendors and contractors to
workout details
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Acceptance Phase Commissioning
• Functional performance tests
– Often referred to as the “commissioning” phase
in a project schedule
– Verifies the intended operation of individual
components and associated controls under
various conditions and modes of operation
– Test plans prepared to verify the complete
sequence of operations
– Testing from components to systems
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HVAC Pre-Functional Issues
Sometimes the obvious is missed...
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HVAC Pre-Functional Issues
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HVAC Functional Performance Issues
• Example, Municipal
Office Building:
– Programming error prevented
morning warm-up cycle on
RTU,
– causing winter warm-up to
be done by electric reheat.
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HVAC Functional Performance Issues
• Example,
packaged RTU:
winter night
setback mode
– the outside air
damper was open
to 40% minimum
position,
– when it should be
closed.
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HVAC Short-Term Diagnostic Testing Issues
• Scheduling: equipment found on at night
or weekends
• System operation above or below setpoint
• Excessive cycling of equipment
• Malfunctioning controls (economizers, reset
schedules)
• Controls permanently overridden
• Simultaneous heating and cooling
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Warranty Phase Commissioning
• Warranty period / seasonal testing
– Seasonal variation in operations or control
strategies may require additional testing during
the opposite season to verify performance
– Depends on season during functional
performance testing
– Review operation before warranty period expires
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: Commissioning
Section 3: Retro-commissioning
Section 4: Case Studies
Section 5: Costs and Benefits
Section 6: Resources
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Where to Start?
• Retrofit or Retro-commission?
– Is the equipment efficient?
– Is the equipment appropriate for the loads?
– Is it optimally controlled?
• Need a benchmark
• What is EUI?
– Energy Utilization Index
• Btu/sf/year
• kWh/sf/year
• W/sf
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Where to Start?
• Energy Utilization Index
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Where to Start?
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Where to Start?
• How about comfort and maintenance?
– Is the facility staff chasing comfort
problems?
– Does “putting out fires” lead to no time for
routine maintenance?
• Comfort
– Poor comfort control
excessive energy
use
– Poor comfort
something is not right
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Where to Start?
• Retrofit
– If equipment is past its life
– If lighting is incandescent or T-12
– If building use is dramatically different than the
original design
– If controls are not maintainable
– If large AHUs run because there is a new
computer room
• Mis-match of equipment to load and use
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Where to Start?
• Retro-commission
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Controls tune-up
Existing controls are useful
Existing controls are not optimized
Control programs have been “butchered”
Sensor calibration is a concern
Actuators are failing
Sequences are inefficient
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Retro-commission vs. Retrofit
• Retro-commission
– Lower cost
– Fast payback
• Retrofit
– Higher cost
– Longer payback
– Savings are more persistent
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How to Decide
• Retrofit and retro-commissioning can
happen together
• Mechanical problems should not be fixed
with more controls
• Mechanical problems fixed with mechanical
design
• Control problems fixed with retrocommissioning
• Apply whichever is appropriate
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Retro-commissioning Process
Planning
Prepare
RCx Plan,
Preliminary
Investigation
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Investigation
Detailed
Analysis,
Short-Term
Monitoring,
Payback
Analysis
Implementation
Measures
Get
Implemented
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Verification
Occupancy
Perform
Functional
Testing,
Resolve
Deficiencies
Staff
Training,
Define
Seasonal
Testing,
Measurement
And
Verification
Retro-commissioning Process
• Who does the work?
• Retro-commissioning provider generally
does not make program changes or install
or repair equipment
• Retro-commissioning provider subcontracts
• Owner hires directly, Retro-commissioning
manages work
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Retro-commissioning Process
• Short-Term Monitoring
• Data collection of
existing equipment
operation
• Used to understand
existing control
strategies
• Use Building
automation system or
dataloggers
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Short-Term Monitoring
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Retro-commissioning Opportunities
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Scheduling and optimum start/stop
Fixed system setpoints vs. variable
Failing control hardware
Economizers
Balance valves on large pumps
VAV box scheduling
Rewrite and reprogram sequences
Outside air control
Return fan control
Lighting Control
Demand Control
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Scheduling
• Still the most powerful EMS tool
• One of the biggest sources of energy
waste
– Schedules creep longer and longer
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Optimum Start
• One of the oldest EMS strategies
• Many ways to accomplish it
• Basically takes into account OAT, Zone
Temp & recovery ability of HVAC
equipment
• Starts the equipment just early enough to
meet setpoint at the beginning of
occupancy
• Adaptive Learning or not?
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Optimum Start
• Applicable to Air Handlers or zones
– Zones or AHU send request to central plants to
operate if needed
• Decide if you want optimum start heating
or cooling or both
• Keep outdoor air dampers closed during a
morning warm-up optimum start period
• Specify a maximum “look-ahead window” of
X hours
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Optimum Stop
• Stops the facility systems prior to
scheduled stop time to let the building
“coast” to the end
• Use the mass of the building and comfort
delivery systems to maintain comfort
without heating or cooling
• Especially good for electric heat
• Optimum stop ~30 to 45 minutes early
• Don’t turn the air off!!
– may depend on occupants
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Fixed or Variable Setpoints
• Fixed setpoints are rarely efficient
• Central plant and AHU setpoints to match
the building load
• 55F AHU discharge air is for design days
• 44F chilled water is not always necessary
• Setpoints should self-adjust
– Provide only enough cooling to meet the load
– Maximize return air heating
– Minimize air duct losses
© Architectural Energy Corporation
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Fixed or Variable Setpoints
• Heating Water Plant
– If occupied, enable ~60F outdoor temp
– If all AHU are off, enable at ~50F
• Reduce heating plant runtime
– less energy
– less maintenance
– Close the hot water valves!
• Coil radiative losses can be extensive
• Compromise with maintenance and control MAT
to 50F
© Architectural Energy Corporation
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Fixed or Variable Setpoints
• A reset dynamically adjusts a setpoint
based on another variable
– Used to match a setpoint to the process load
– Good -Can be a linear fixed slope between 2
conditions
OAT
AHU DAT
90F
55F
20F
65F
– Better -Can use a PID to determine the setpoint
based on 1 condition and 1 target number
• Self-adjusts to find the best setpoint for the
current conditions
© Architectural Energy Corporation
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Fixed or Variable Setpoints
• Monitor VAV dampers and valves for AHU
setpoints
• Monitor AHU valves for central plant
setpoints
• Use “request for heating” or “cooling”
– Enable plants on load request, not OAT
© Architectural Energy Corporation
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Fixed or Variable Setpoints
• What to reset….
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Zone setpoint
Duct static pressure setpoint
Discharge air temperature setpoint
Supply water temperature
Condenser water temperature setpoint
Heat Pump condenser water temperature
Building static pressure setpoint
Lighting level
• Need to be careful not to have too many
resets on one system!
© Architectural Energy Corporation
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Failing Control Hardware
• Broken actuators & linkages & leaky valves
– Pneumatic actuator diaphragms
– Linkages come loose
– Globe valve and zone valves can leak
• Sensor calibration
– Key sensors need regular calibration
• Outside air temp and humidity
• Supply air and water temps
© Architectural Energy Corporation
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Economizers
• Packaged RTU economizers
– Very high failure rate after couple years
– Cheap damper connection
– Failed sensor, actuator or binding damper
• All economizers
– Disable economizer mode too early
– Many economizing hours lost
– Humidity sensors and enthalpy switchover
© Architectural Energy Corporation
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Balance Valves
• Balance valves on large pumps
– 15% open valve restricts flow 85%
– Open valve, change impeller size
– Reduce HP and losses
• Example:
– 30HP pump
– Balance valve 65% open
– Save 3kW and 3800 kWh = ~$150/yr
© Architectural Energy Corporation
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VAV Box Scheduling
• Zone scheduling
• VAV box minimum airflow: min to zero
– Occupied box = minimum airflow
– Unoccupied box = zero airflow
• Turn off AHU
– Use occupancy override buttons
– Only the occupied zones get airflow
– 80% of the building is unoccupied at 5PM
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Rewrite and Reprogram Sequences
• Are the original sequences optimized?
• Or are they designed for the worst-case
scenario?
• Re-commission instead of retrocommissioning
• Sequences should have:
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Optimum start/stop
Variable setpoints
System setpoints that match the loads
Proper economizer switchover
Optimized plant control
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Minimum Outside Air
• How to measure (air flow, calculate, etc)
• How much is needed
• Variable air Volume challenges
– ASHRAE 62 requires OA CFM maintain as supply
air varies, or set OA at min supply CFM
• Drop the setting when 90% of the
occupants leave at 5:30PM
– But keep building pressure positive!
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Minimum Outside Air
• OA need based on CO2 concentration
– “Demand Controlled Ventilation”
• 2005 Title 24 Code – Section 121
– CO2 Sensor in each room that has a design
occupancy >= 25 people per 1000SF
• With a few exceptions…
• 600 ppm above ambient
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Lighting Control
• Parking lot lights
– Timeclock
– Astronomical clock
– Photocell
• Interior lights
– Schedule with DDC
– Occupancy sensors
– Photocell on/off
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Demand Control
• Electrical demand control and load
shedding
• Turn off equipment or adjust setpoints
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DX lockout
Increase CHW setpoint
Lobby lights
Zone setpoint reset
• Measure building kW
• Keep the building below kW setpoint
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Compressor Operation
• Packaged RTU DX systems
• Y1 and Y2 with 3 or more
compressors
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Compressor Operation
• Case Study- Park Meadows Mall
– 4 compressors, with 2 output signals
– Convert to 4 cooling signals
– Reduce short-cycling
– Allow for demand control
– Reduce peak demand
– Savings
• 65kW, and 85,439 kWh/Summer
• ~$10,000 per summer
© Architectural Energy Corporation
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Compressor Operation
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Strategies in Order of Energy Savings
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Scheduling
Optimum Start
Optimum Stop
Minimum Outside air control and
economizers
Setpoint resets
Demand Limiting
Load Based Control
Return fan control
Balance valves and impellers
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: Commissioning
Section 3: Retro-commissioning
Section 4: Case Studies
Section 5: Costs and Benefits
Section 6: Resources
© Architectural Energy Corporation
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Case Study: Century Middle School
• 116,000 SF, 4-year old
School
– Highest Energy
Utilization Index in
district
– Large number of comfort
complaints
– Reduced natural gas use
by 48%
– Reduced electrical
energy use by 22%
© Architectural Energy Corporation
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Case Study: Century Middle School
• Mechanical System Description
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Chiller Plant with Cooling Tower
Boiler Plant
8 Constant Volume Air Handlers
83 Reheat Coils
Crawl Space relief fans for pressure control
New CSI DDC system
© Architectural Energy Corporation
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Case Study: Century Middle School
Retro-commissioning Plan
• Identify control problems
– Develop plan to repair or replace control
equipment
• Many pneumatic actuators found disconnected
• Pneumatic transducers incorrectly calibrated
• Identify comfort problems
• Identify occupancy patterns
– Match Equipment Schedules with Use
• Short-term monitored data collection and
analysis
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Case Study: Century Middle School
• Short-term Monitoring - HVAC Energy Data
© Architectural Energy Corporation
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Case Study: Century Middle School
• Short-term Monitoring - Lighting Energy
Data (Occupancy Indicator)
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Case Study: Century Middle School
• Short-term Monitoring Revealed
– All AHU discharge air resets “broke”
• 55F air temp at all times because the reset was to
return air temperature
– All AHU overheat every night
• Hot Water valves control to 100F discharge air;
Sensor is 15’ away from coil
• Major loss of boiler energy during unoccupied
hours
– Hot water supply temperature reset “broke”
• Programming errors
• Boiler limit controllers fighting with DDC control
© Architectural Energy Corporation
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Case Study: Century Middle School
© Architectural Energy Corporation
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Case Study: Century Middle School
$65,000 of Natural Gas Savings From
Dec ‘01 to Feb ‘03
© Architectural Energy Corporation
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Case Study: Niver Creek Middle School
• 105,000SF, 30-year old School
– 15 Multi-Zone DX Rooftop Units
– 1 Variable Volume Unit
– Boiler Plant
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Case Study: Niver Creek Middle School
• Overall Project Scope
– Replace old DDC system with new (450 points)
– Replace 4 multizone roof top units with new
– Re-balance all air and water systems
• Commissioning Scope
– Perform existing mechanical evaluation to
determine project scope
– Re-write all equipment sequences
• Include setpoint resets to minimize energy use
– Commission all existing and new HVAC
equipment
© Architectural Energy Corporation
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Case Study Energy Results: kWh
© Architectural Energy Corporation
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Case Study Energy Results: Gas
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: Commissioning
Section 3: Retro-commissioning
Section 4: Case Studies
Section 5: Costs and Benefits
Section 6: Resources
© Architectural Energy Corporation
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Commissioning Costs
• Typical cost: $0.50 to $2.00 per SF
• Typical energy savings: 6 to 12 percent
• Median payback: ~ 5 years (from energy
savings)
• Other cost estimate methods:
– .5 to 2 percent of total construction cost
– 2 to 4 percent of equipment/installation cost of
systems to be commissioned (i.e. mechanical
system cost, electrical system cost)
Data from proceedings of 1997 National Conference on Building Commissioning/Oregon Office of Energy
Cost-effectiveness of Commercial Buildings Commissioning – A Meta-Analysis of Energy and Non-Energy Impacts in Existing
Buildings and New Construction in the United States, LBNL, PECI, Energy Systems Lab – TAMU, 2004
© Architectural Energy Corporation
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Retro-commissioning Costs
• Typical fees: $0.20 to $0.90 per SF
• Typical implementation cost:
– Office buildings - $0.20 to $0.50 per SF
– Labs and hospitals are more costly
• Typical energy savings: 7 to 30 percent
• Median payback: > .7 years
Data from proceedings of 1997 National Conference on Building Commissioning/Oregon Office of Energy
Cost-effectiveness of Commercial Buildings Commissioning – A Meta-Analysis of Energy and Non-Energy Impacts in Existing
Buildings and New Construction in the United States, LBNL, PECI, Energy Systems Lab – TAMU, 2004
© Architectural Energy Corporation
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Commissioning Benefits
• Consider the potential costs of not
commissioning:
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Professional liability claims
Owner litigation exposure
Unhappy owner
Unhappy building occupants
Unhappy O+M staff
Higher energy costs
Continuing callbacks to solve problems and
warranty claims
© Architectural Energy Corporation
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Webcast Outline
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Section 1: What is Commissioning?
Section 2: The Commissioning Process
Section 3: Commissioning Case Studies
Section 4: Commissioning Costs and
Benefits
• Section 5: Resources
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Commissioning Resources
• Building Commissioning Association web
site
– http://www.bcxa.org
• PECI (Portland Energy Conservation, Inc.)
– http://www.peci.org
• ASHRAE Guidelines 0 & 1
– http://www.ashrae.org
• California Commissioning Collaborative
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http://www.cacx.org
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Energy Design Resources
• www.energydesignresources.com
• Commissioning Guidelines and Design
Brief
• Commissioning Assistant On-line
software
• Technical Design Briefs and Guidelines
• Case Studies
• Software tools (Skycalc, SPOT, eQuest)
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Savings By Design Program
• www.savingsbydesign.com
• Set guidelines for exceeding T-24
standards
• Design assistance
• Incentives for owner ($150k max)
• Incentives for design team ($50k max)
• Design approaches: System and whole
building
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Energy Efficiency Resources
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www.pge.com/biz
New construction design assistance
Cash incentives
Customized energy efficiency/demand
response incentives
• Energy efficiency equipment rebates
• Self generation incentives and rates
• Education and training
© Architectural Energy Corporation
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Energy Efficiency Resources
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• www.smud.org/commercial/saving/incentives.
html
• www.sdge.com/business/bus_energy_efficiency
.shtml
• www.sce.com/RebatesandSavings/
• www.socalgas.com/energyefficiency/
© Architectural Energy Corporation
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Thank you for participating
in this Webinar
Erik Jeannette, PE
Architectural Energy Corporation
Boulder, Colorado
www.archenergy.com
© Architectural Energy Corporation