Army Reserve Center
Newport, Rhode Island
Alexander Hosko
Mechanical Option
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Alexander Hosko
Mechanical Option
Spring 2011
General Building Information
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Location: Newport, Rhode Island
Size: 59,000 square feet
Levels: 2 levels
Cost: $17 million
Construction Time: January 2009 – September 2011
Delivery Method: Design-Bid-Build
Alexander Hosko
Mechanical Option
Spring 2011
General Building Information
1st Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
2nd Floor
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
Airside
Waterside
- 1 constant volume air handling unit (AHU)
- 2100 CFM
To cool the building:
-2 air-cooled rotary screw packaged water chillers
-40 and 52 tons
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- 2 variable air volume air handling units
- 3700 CFM and 13200 CFM
- Unit ventilators
- 8 total between 400 and 1600 CFM
To heat the building:
-2 natural gas boilers
-each 960 MBH
Controls
- Direct Digital Control (DDC) by Johnson Controls
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
1st Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
AHU-1
2nd Floor
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
1st Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
AHU-1
AHU-2
2nd Floor
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
1st Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
AHU-1
AHU-2
AHU-3
2nd Floor
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
1st Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
AHU-1
AHU-3
AHU-2
UV
2nd Floor
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
1st Floor
2nd Floor
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
AHU-1
AHU-3
AHU-2
UV
UH AND DSS
Alexander Hosko
Mechanical Option
Spring 2011
Existing Mechanical Systems
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Total Energy Use:
1, 227 mmBtu / yr
Cost of Energy Use:
$27, 384 / year
First Cost:
$301,410
LEED:
36 – 42 Points = Silver or Gold
Alexander Hosko
Mechanical Option
Spring 2011
Design Objectives
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Reduce Aspect Ratios of Ducts
- Reduce Total Cost of Ductwork
- Reduce Energy Required for Supply Fans
- Reduce Total Energy Consumption
- Maintain Current LEED Silver or Gold Rating or Improve Upon
Alexander Hosko
Mechanical Option
Spring 2011
Variable Refrigerant Flow System
Summary
Presentation Outline
- Condenser (rooftop) connected to multiple indoor evaporators
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- DOAS to handle outside air and latent load requirements
- VRF to handle remaining sensible load
Alexander Hosko
Mechanical Option
Spring 2011
Variable Refrigerant Flow System
Benefits
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Simultaneous heating and cooling – allows for Heat Recovery
- Max COP of 5.68 compared to 2.90 for chiller
- Rooftop Condensing Units lead to saved mechanical space (replace
boilers)
- Pipes take up less space than ductwork
- Leads to reduced building height / cost in some cases
Alexander Hosko
Mechanical Option
Spring 2011
Variable Refrigerant Flow System
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Total Energy Use:
1018 mmBtu / yr
Cost of Energy Use:
$27, 784 / year
First Cost:
$283,105
LEED:
43 – 49 Points = Gold
Alexander Hosko
Mechanical Option
Spring 2011
Ground Couple Heat Pump
Summary
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Uses Earth as a heat source / sink
- Send fluid through pipes in ground to heat or cool fluid
- Takes advantage of 50 – 60 °F constant ground temperature
- Heat exchanger to bring heat into / out of system
- DOAS to handle latent loads and outside air
- Boilers to meet heating when GCHP is not enough
Benefits
- Less ductwork
- Save energy
Alexander Hosko
Mechanical Option
Spring 2011
Ground Couple Heat Pump
Types
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Vertical
- Pipes are placed downward into ground
- Two small diameter tubes / borehole
- Boreholes 50 feet to 600 feet deep
- Boreholes 20 feet apart to prevent thermal interference
Horizontal
- Pipes are placed about 4 feet deep
- Single or multiple pipe / trench
- If multiple, further distance because of thermal interference
Vertical
Horizontal
Alexander Hosko
Mechanical Option
Spring 2011
Vertical Ground Couple Heat Pump
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Advantages
-
Smaller amount of land required
More constant thermal properties of soil
More efficient than horizontal GCHP
Smallest amount of pumping / piping energy
Disadvantages
- Cost
- Difficult to find experienced contractors
Alexander Hosko
Mechanical Option
Spring 2011
Vertical Ground Couple Heat Pump
Vertical GCHP Pipe Length Required
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Method of Ingersoll and Zobel
- Based on heat transfer from cylinder buried in earth
For Cooling:
For Heating:
Variables are determined based on:
-
Loads for the Building
Average Heat Transfer to the Ground
Thermal Resistance of the Ground and Pipe
Ground Temperature
Proximity of Adjacent Bores
Liquid Temperature at Heat Pump Inlet / Outlet
Power Input at Design Cooling / Heating Loads
Alexander Hosko
Mechanical Option
Spring 2011
Vertical Ground Couple Heat Pump
Vertical GCHP Pipe Length Required
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Using Equation Above:
Total Length for Cooling: 15,424 feet
Total Length for Heating: 23,048 feet
Use the greater of two values:
23,048 feet
3 Boreholes / Loop
600 Feet Deep
20 Feet between Borehole
Alexander Hosko
Mechanical Option
Spring 2011
Vertical Ground Couple Heat Pump
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
Total Energy Use:
878 mmBtu / yr
Cost of Energy Use:
$23, 733 / year
First Cost:
$502, 086
LEED:
46 – 52 Points = Gold to Platinum
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
SYSTEM COMPARISON
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
ANNUAL ENERGY USE (mmBtu/yr) FIRST COST ANNUAL ENERGY COST
VAV
VRF
GSHP
1,227
1018
878
$301,410.00
$283,105.00
$502,086.00
$27,384.00
$27,784.00
$23,733.00
- GCHP uses least energy and has least cost of energy
- Simple payback of 54 years – unfeasible
- VRF is the best choice overall
- Save mechanical space
- Uses less energy than existing VAV
- Lowest first cost
MECHANICAL
SPACE SAVED (FT)
800
-
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
SYSTEM COMPARISON
Factors Effecting Cost
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Extra maintenance cost not included with VRF
- $40,000 / year (at least) if extra personnel required
- One time cost if training required
ANNUAL ENERGY USE (mmBtu/yr) FIRST COST ANNUAL ENERGY COST
VAV
VRF
GSHP
1,227
1018
878
$301,410.00
$283,105.00
$502,086.00
$27,384.00
$27,784.00
$23,733.00
- Extra cost of controls for VRF
- Boilers oversized for existing VAV
- Sized at 66% of total capacity (each)
- If changed, total cost would be $292,193
- Prices for VRF determined by Daiken VRV Specs
- Converted from euros to dollars
- Used RS Means for installation costs
- May be slightly higher due to less familiar system
- May be more expensive to purchase units in U.S.
MECHANICAL
SPACE SAVED (FT)
800
-
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Natural gas ranges from $ 4.00 / mmBtu to $12.00 / mmBtu
- Currently $4.00 / mmBtu
- Cost of VRF energy use is more expensive even though it uses less
energy because it uses all electricity
- Electricity is expensive relative to natural gas
- 12.7% electricity in region is generated by natural gas
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
If natural gas doubles….
- electricity goes up 12.7%
- natural gas goes up 100%
If natural gas triples….
- electricity goes up 27.0%
- natural gas goes up 200%
SYSTEM COMPARISON
SYSTEM COMPARISON
ANNUAL ENERGY USE (mmBtu/yr) FIRST COST ANNUAL ENERGY COST
VAV
VRF
GSHP
1,227
1018
878
$301,410.00
$283,105.00
$502,086.00
- VRF uses $464 / year less than VAV
$31,777.00
$31,313.00
$26,779.00
MECHANICAL
SPACE SAVED (FT)
800
-
ANNUAL ENERGY USE (mmBtu/yr) FIRST COST ANNUAL ENERGY COST
VAV
VRF
GSHP
1,227
1018
878
$301,410.00
$283,105.00
$502,086.00
- VRF uses $1,306 / year less than VAV
$36,595.00
$35,289.00
$30,207.00
MECHANICAL
SPACE SAVED (FT)
800
-
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
Aspect Ratio Problem
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
ground couple heat pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- The Aspect Ratio of the ducts will still be high on the first floor
- Greatly reduced on second floor
VAV
AREA SERVED
CFM (MAX)
AHU-1 FIRST FLOOR OFFICES
3700
AHU-2
SECOND FLOOR
13200
AHU-3
ASSEMBLY
2100
UV-1
CLASSROOM
625
UV-2
CLASSROOM
440
UV-3
CLASSROOM
440
UV-4 SOUTH SUPPLY OFFICES
606
UV-5 WEST SUPPLY OFFICES
650
UV-6 WEAPONS SIMULATOR
975
UV-7
SIPRNET CAFÉ
1575
UV-8
MAILROOM SUITE
375
AHU-1
AHU-3
AHU-2
UV
UH AND DSS
VRF
AREA SERVED
CFM (MAX)
AHU-1 1ST FLOOR AND SPACES PREVIOUSLY ON UVS
9200
AHU-2
SECOND FLOOR
4600
AHU-3
ASSEMBLY
3000
Alexander Hosko
Mechanical Option
Spring 2011
System Comparison
Achieving Design Objectives?
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
ground couple heat pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Aspect Ratio
- Improved on second floor
- The same on first floor but not worse
- LEED
- VRF will achieve LEED Gold
- GCHP will achieve LEED Gold or Platinum
- Energy Improvement
- VRF will use 83% of existing VAV
- GCHP will use72% of existing VAV
Alexander Hosko
Mechanical Option
Spring 2011
Structural Breadth
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- With VRF System, will need to place condensing VRV units on the
roof changing the structural requirements
- Mass of each unit according to specifications:
TAG MANUFACTURER MODEL MASS (LB)
VRV-1
DAIKIN
REYQ96PYDN
732
VRV-2
DAIKIN
REYQ120PYDN 732
VRV-3
DAIKIN
REYQ168PYDN 1036
VRV-4
DAIKIN
REYQ168PYDN 1036
VRV-5
DAIKIN
REYQ72PYDN
732
VRV-6
DAIKIN
REYQ96PYDN
732
Alexander Hosko
Mechanical Option
Spring 2011
Structural Breadth
Presentation Outline
- Addition of VRV units leads to dead load of 11psf as shown below:
TOTAL DEAD LOAD (psf)
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
VRV UNITS
STANDING SEAM METAL ROOF
INSULATION
APPROXIMATE DECK SELF WEIGHT
TOTAL
3
2
3
3
11
- Total load 61 psf when 20 psf live load and 30 psf snow load are
included
Alexander Hosko
Mechanical Option
Spring 2011
Structural Breadth
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Thus, need to use the following to support additional load:
- Vulcraft 1.5B20 roof deck
- 28K8 joists
- W10x54 girders
Alexander Hosko
Mechanical Option
Spring 2011
Acoustical Breadth
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Daikin VRV Units will be placed as shown on right
- Space below units is office space
- Max noise level of 40 – 45 dBA in office space
- Max noise level on roof will occur at point X or next to VRV - 3 or
VRV - 4
Alexander Hosko
Mechanical Option
Spring 2011
Acoustical Breadth
- Decibels produced by each unit shown in table below:
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
TAG
VRV-1
VRV-2
VRV-3
VRV-4
VRV-5
VRV-6
DIAKIN VRV UNITS
MODEL
REYQ96PYDN
REYQ120PYDN
REYQ168PYDN
REYQ168PYDN
REYQ72PYDN
REYQ96PYDN
dBA
58
60
61
61
58
58
Use following equation to determine sound intensity from each
VRV Unit at point X:
I1 / I2 = (d2 / d1)2
I1 = intensity at point 1
I2 = intensity at point 2
d1 = distance from source to intensity 1
d2 = distance from source to intensity 2
Alexander Hosko
Mechanical Option
Spring 2011
Acoustical Breadth
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- Decibel addition (as shown below) allows dB to be added to find
sound at point X
- Sound at X is 53 dB
- Less than sound at VRV – 3 and VRV – 4 (both at 61 dBA)
- Transmission loss through roof is 35 dBA
- Thus, total sound from VRV Units is 26 dBA which is below
40-45 dBA and will not be a problem in the office
Alexander Hosko
Mechanical Option
Spring 2011
Presentation Outline
General Building Information
Existing Mechanical Systems
Design Objectives
Variable Refrigerant Flow System
Ground Couple Heat Pump System
System Comparison
Structural Breadth
Acoustical Breadth
Questions
- The Pennsylvania State University Architectural Engineer Faculty and
Staff
- Thesis Advisor: Dr. Stephen Treado
Questions?
- Michael Baker Corporation: Specifically Duncan Penney and Doug
Barker
- U.S. Army Corps of Engineers
- Family and Friends for their support