HTML has links - PDF has Authentication
51-11C-80100  <<  51-11C-80500 >>   51-11C-90000

(Effective until July 1, 2020)

PDFWAC 51-11C-80500

Appendix DRenewable energy.

AE101.1 On-site renewable energy systems. Each new commercial building or addition larger than 5,000 square feet of gross conditioned floor area shall include a renewable energy generation system consisting of at least 70 watts rated peak photovoltaic energy production, or 240 kBtu of annual solar water heating energy production, per 1,000 square feet of conditioned floor area or fraction thereof. For buildings over 5 stories in height, the conditioned area for this calculation shall be based on the conditioned area of the largest 5 above-grade stories in the building. If the on-site renewable energy option in C406 is selected, this energy shall be in addition to that required by C406.
EXCEPTION:
Alternate means of achieving equivalent energy savings are permissible where approved by the code official, if the calculated net annual energy savings equals or exceeds the calculated annual energy production of the required on-site renewable energy system.
[Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-80500, filed 1/19/16, effective 7/1/16.]
(Effective July 1, 2020)

PDFWAC 51-11C-80500

Appendix DCalculation of HVAC total system performance ratio.

D101 Scope. This appendix establishes criteria for demonstrating compliance using the HVAC total system performance ratio (HVAC TSPR) for systems serving office, retail, library and education occupancies and buildings, which are subject to the requirements of Section C403.3.5 without exceptions. Those HVAC systems shall comply with Section C403 and this appendix as required by Section C403.1.1.
D201 Compliance. Compliance based on HVAC total system performance ratio requires that the provisions of Section C403.3 are met and the HVAC total system performance ratio of the proposed design is more than or equal to the HVAC total system performance ratio of the standard reference design. The HVAC TSPR is calculated according to the following formula:
HVAC TSPR = annual heating and cooling load/annual carbon emissions from energy consumption of the building HVAC systems
Where:
 
 
Annual carbon emissions from energy consumption of the building HVAC systems
=
sum of the annual carbon emissions in pounds for heating, cooling, fans, energy recovery, pumps, and heat rejection calculated by multiplying site energy consumption by the carbon emission factors from Table C407.1
Annual heating and cooling load
=
sum of the annual heating and cooling loads met by the building HVAC system in thousands of Btus.
Table C407.1 (Reprinted from Chapter 4)
Carbon Emissions Factors
Type
CO2e (lb/unit)
Unit
Electricity
0.70
kWh
Natural gas
11.70
Therm
Oil
19.2
Gallon
Propane
10.5
Gallon
Othera
195.00
mmBtu
On-site renewable energy
0.00
 
a
District energy systems may use alternative emissions factors supported by calculations approved by the code official.
D300 Simulation program.
D301 General.
D302 Calculation of the HVAC TSPR for the Standard Reference Design. The simulation program shall calculate the HVAC TSPR based only on the input for the proposed design and the requirements of this appendix. The calculation procedure shall not allow the user to directly modify the building component characteristics of the standard reference design.
D303 Specific approval. Performance analysis tools meeting the applicable subsections of Appendix D and tested according to ASHRAE Standard 140 shall be permitted to be approved. Tools are permitted to be approved based on meeting a specified threshold for a jurisdiction. The code official shall be permitted to approve tools for a specified application or limited scope.
D400 Climatic data. The simulation program shall perform the simulation using hourly values of climatic data, such as temperature and humidity, using TMY3 data for the site as specified here: https://buildingenergyscore.energy.gov/resources
D500 Documentation. Documentation conforming to the provisions of this section shall be provided to the code official.
D501 Compliance report. Building permit submittals shall include:
1. A report produced by the simulation software that includes the following:
1.1 Address of the building.
1.2 Name of individual completing the compliance report.
1.3 Name and version of the compliance software tool.
1.4 The dimensions, floor heights and number of floors for each block.
1.5 By block, the U-factor, C-factor, or F-factor for each simulated opaque envelope component and the U-factor and SHGC for each fenestration component.
1.6 By block or by surface for each block, the fenestration area.
1.7 By block, a list of the HVAC equipment simulated in the proposed design including the equipment type, fuel type, equipment efficiencies and system controls.
1.8 The HVAC total system performance ratio for both the standard reference design and the proposed design.
2. A mapping of the actual building HVAC component characteristics and those simulated in the proposed design showing how individual pieces of HVAC equipment identified above have been combined into average inputs ad required by Section D601.11 including:
2.1 Fans.
2.2 Hydronic pumps.
2.3 Air handlers.
2.4 Packaged cooling equipment.
2.5 Furnaces.
2.6 Heat pumps.
2.7 Boilers.
2.8 Chillers.
2.9 Cooling towers.
2.10 Electric resistance coils.
2.11 Condensing units.
2.12 Motors for fans and pumps.
2.13 Energy recovery devices.
For each piece of equipment identified above, include the following as applicable:
2.14 Equipment name or tag consistent with that found on the design documents.
2.15 Efficiency level.
2.16 Capacity.
2.17 Input power for fans and pumps.
3. Floor plan of the building identifying how portions of the building are assigned to the simulated blocks and areas of the building that are not covered under the requirements of Section C403.1.1.
D600 Calculation procedure. Except as specified by this appendix, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.
D601 Simulation of the proposed building design. The proposed design shall be configured and analyzed as specified in this section.
D601.1 Utility rates. For the purpose of calculating the HVAC TSPR the following simple utility rate determined by the Washington state department of commerce shall be used:
$0.112/kWh of electricity.
$1.158/therm of fossil fuel.
D601.2 Block geometry. The geometry of buildings shall be configured using one or more blocks. Each block shall define attributes including block dimensions, number of floors, floor to floor height and floor to ceiling height. Simulation software may allow the use of simplified shapes (such as rectangle, L shape, H shape, U shape or T shape) to represent blocks. Where actual building shape does not match these predefined shapes, simplifications are permitted providing the following requirements are met:
1. The conditioned floor area and volume of each block shall match the proposed design within 10 percent.
2. The area of each exterior envelope component from Table C402.1.4 is accounted for within 10 percent of the actual design.
3. The area of vertical fenestration and skylights is accounted for within 10 percent of the actual design.
4. The orientation of each component in 2 and 3 above is accounted for within 45 degrees of the actual design.
The creation of additional blocks may be necessary to meet these requirements.
EXCEPTION:
Portions of the building that are unconditioned or served by systems not covered by the requirements of Section C403.1.1 shall be omitted.
D601.2.1 Number of blocks. One or more blocks may be required per building based on the following restrictions:
1. Each block can have only one occupancy type (office, library, education or retail). Therefore, at least one single block shall be created for each unique use type.
2. Each block can be served by only one type of HVAC system. Therefore, a single block shall be created for each unique HVAC system and use type combination. Multiple HVAC units of the same type may be represented in one block. Table D601.10.2 provides directions for combining multiple HVAC units or components of the same type into a single block.
3. Each block can have a single definition of floor to floor or floor to ceiling heights. Where floor heights differ by more than 2 feet, unique blocks should be created for the floors with varying heights.
4. Each block can include either above grade or below grade floors. For buildings with both above grade and below grade floors, separate blocks should be created for each. For buildings with floors partially above grade and partially below grade, if the total wall area of the floor(s) in consideration is greater than or equal to 50 percent above grade, then it should be simulated as a completely above grade block, otherwise it should be simulated as a below grade block.
5. Each wall on a façade of a block shall have similar vertical fenestration. The product of the proposed designU-factor times the area of windows (UA) on each façade of a given floor cannot differ by more than 15 percent of the average UA for that façade in each block. The product of the proposed design SHGC times the area of windows (USHGC) on each façade of a given floor cannot differ by more than 15 percent of the average USHGC for that façade in each block. If either of these conditions are not met, additional blocks shall be created consisting of floors with similar fenestration.
6. For a building model with multiple blocks, the blocks should be configured together to have the same adjacencies as the actual building design.
D601.3 Thermal zoning. Each floor in a block shall be modeled as a single thermal zone or as five thermal zones consisting of four perimeter zones and a core zone. Below grade floors shall be modeled as a single thermal block. If any façade in the block is less than 45 feet in length, there shall only be a single thermal zone per floor. Otherwise each floor shall be modeled with 5 thermal zones. A perimeter zone shall be created extending from each façade to a depth of 15 feet. Where facades intersect, the zone boundary shall be formed by a 45 degree angle with the 2 facades. The remaining area or each floor shall be modeled as a core zone with no exterior walls.
D601.4 Occupancy.
D601.4.1 Occupancy type. The occupancy type for each block shall be consistent with the building area type as determined in accordance with Section C405.4.2.1. Portions of the building that are building area types other than office, school (education), library, or retail shall not be included in the simulation.
D601.4.2 Occupancy schedule, density, and heat gain. The occupant density, heat gain, and schedule shall be for office, retail, library, or school as specified by ASHRAE Standard 90.1 Normative Appendix C.
D601.5 Envelope components.
D601.5.1 Roofs. Roofs will be modeled with insulation above a steel roof deck. The roof U-factor and area shall be modeled as in the proposed design. If different roof thermal properties are present in a single block, an area weighted U-factor shall be used. Roof solar absorbtance shall be modeled at 0.70 and emittance at 0.90.
D601.5.2 Above grade walls. Walls will be modeled as steel frame construction. The U-factor and area of above grade walls shall be modeled as in the proposed design. If different wall constructions exist on the façade of a block an area-weighted U-factor shall be used.
D601.5.3 Below grade walls. The C-factor and area of below grade walls shall be modeled as in the proposed design. If different slab on grade floor constructions exist in a block, an area-weighted C-factor shall be used.
D601.5.4 Above grade exterior floors. Exterior floors shall be modeled as steel frame. The U-factor and area of floors shall be modeled as in the proposed design. If different wall constructions exist in the block an area-weighted U-factor shall be used.
D601.5.5 Slab on grade floors. The F-factor and area of slab on grade floors shall be modeled as in the proposed design. If different below grade wall constructions exist in a block, an area-weighted F-factor shall be used.
D601.5.6 Vertical fenestration. The window area and area weighted U-factor and SHGC shall be modeled for each façade based on the proposed design. Each exterior surface in a block must comply with Section D601.2.1 item 5. Windows will be combined in to a single window centered on each façade based on the area and sill height input by the user.
D601.5.7 Skylights. The skylight area and area weighted U-factor and SHGC shall be modeled for each floor based the proposed design. Skylights will be combined in to a single skylight centered on the roof of each zone based on the area and sill height input by the user.
D601.6 Lighting. Interior lighting power density shall be equal to the allowance in Table C405.4.2(1) for office, retail, library, or school. The lighting schedule shall be for office, retail, library, or school as specified by ASHRAE Standard 90.1 Normative Appendix C. The impact of lighting controls is assumed to be captured by the lighting schedule and no explicit controls shall be modeled. Exterior lighting shall not be modeled.
D601.7 Miscellaneous equipment. The miscellaneous equipment schedule and power shall be for office, retail, library, or school as specified by ASHRAE Standard 90.1 Normative Appendix C. The impact of miscellaneous equipment controls is assumed to be captured by the equipment schedule and no explicit controls shall be modeled.
D601.8 Elevators. Elevators shall not be modeled.
D601.9 Service water heating equipment. Service water heating shall not be modeled.
D601.10 On-site renewable energy systems. On-site renewable energy systems shall not be modeled.
D601.11 HVAC equipment. HVAC systems shall meet the requirements of Section C403.
D601.11.1 Supported HVAC systems. At a minimum, the HVAC systems shown in Table D601.11.1 shall be supported by the simulation program.
Table D601.11.1
Proposed Building HVAC Systems Supported by HVAC TSPR Simulation Software
System No.
System Name
System Abbreviation
1
Packaged Terminal Air Conditioner
PTAC
2
Packaged Terminal Air Heat Pump
PTHP
3
Packaged Single Zone Gas Furnace
PSZGF
4
Packaged Single Zone Heat Pump (air to air only)
PSZHP
5
Variable Refrigerant Flow (air cooled only)
VRF
6
Four Pipe Fan Coil
FPFC
7
Water Source Heat Pump
WSHP
8
Ground Source Heat Pump
GSHP
9
Packaged Variable Air Volume (dx cooling)
PVAV
10
Variable Air Volume (hydronic cooling)
VAV
11
Variable Air Volume with Fan Powered Terminal Units
VAVFPTU
12
Dedicated Outdoor Air System (in conjunction with systems 1-8)
DOAS
D601.11.2 Proposed building HVAC system simulation. The HVAC systems shall be modeled as in the proposed design with clarifications and simplifications as described in Table D601.11.2. System parameters not described in the following sections shall be simulated to meet the minimum requirements of Section C403. All zones within a block shall be served by the same HVAC system type as described in Section D601.2.1 item 2. Where multiple system components serve a block, average values weighed by the appropriate metric as described in this section shall be used. Heat loss from ducts and pipes shall not be modeled.
EXCEPTION:
Where the building permit applies to only a portion of an HVAC system and remaining components will be designed under a future building permit, the future components shall be modeled to meet, but not exceed, the requirements of Section C403.
Table D601.11.2
Proposed Building System Parameters
Category
Parameter
Fixed or User Defined
Required
Applicable Systems
HVAC System Type
System Type
User Defined
Selected from Table D601.11.1
All
System Sizing
Design Day Information
Fixed
99.6 percent heating design and 1 percent dry-bulb and 1 percent wet-bulb cooling design
All
Zone Coil Capacity
Fixed
Sizing factors used are 1.25 for heating equipment and 1.15 for cooling equipment
All
Supply Airflow
Fixed
Based on a supply-air-to-room-air temperature set-point difference of 20°F
1-11
Fixed
Equal to required outdoor air ventilation
12
Outdoor Ventilation Air
Outdoor Ventilation Air Flow Rate
Fixed
As specified in ASHRAE Standard 90.1 Normative Appendix C, adjusted for proposed DCV control
All
System Operation
Space Temperature Setpoints
Fixed
As specified in ASHRAE Standard 90.1 Normative Appendix C
1-11
Fan Operation - Occupied
User Defined
Runs continuously during occupied hours or cycled to meet load
1-11
Fan Operation - Occupied
Fixed
Fan runs continuously during occupied hours
12
Fan Operation -Night Cycle
Fixed
Fan cycles on to meet setback temperatures
1-11
Packaged Equipment Efficiency
DX Cooling Efficiency
User Defined
Cooling COP without fan energy calculated in accordance with ASHRAE Standard 90.1 Section 11.5.2c.b
1, 2, 3, 4, 5, 7, 8, 9, 11, 12
Heat Pump Efficiency
User Defined
Heating COP without fan energy calculated in accordance with ASHRAE Standard 90.1 Section 11.5.2c.c
2, 4, 5, 7, 8
Furnace Efficiency
User Defined
Furnace thermal efficiencyc
3, 11
Heat Pump Supplemental Heat
Control
Fixed
Supplemental electric heat locked out above 40°F. Runs in conjunction with compressor between 40°F and 0°F.
2, 4
System Fan Power
Design Fan Power (W/cfm)
User Defined
Input electric power for all fans is required to operate at fan system design conditions divided by the supply airflow rate
All
Single Zone System Fan Power During Deadband (W/cfm)
User Defined
W/cfm during deadband for VAV or multispeed single zone fans
3, 4, 5, 6, 7, 8
Variable Air Volume Systems
Part Load Fan Controls
User Defined
VFD included. User specifies presence of static pressure reset
9, 10, 11
Supply Air Temperature Controls
User Defined
If not SAT reset constant at 55°F. SAT reset results in 60°F SAT during low load conditions
9, 10, 11
Minimum Terminal Unit Airflow Percentage
User Defined
Average minimum terminal unit airflow percentage for block weighted by cfm
9, 10, 11
Terminal Unit Heating Source
User Defined
Electric or hydronic
9, 10, 11
Fan Powered Terminal Unit (FPTU) Type
User Defined
Series or parallel FPTU
11
Parallel FPTU Fan
Fixed
Sized for 50 percent peak primary air at 0.35 W/cfm
11
Series FPTU Fan
Fixed
Sized for 50 percent peak primary air at 0.35 W/cfm
11
Economizer
Economizer Presence
User Defined
Yes or No
3, 4, 9, 10, 11
Economizer High Limit
Fixed
75°F fixed dry-bulb
3, 4, 9, 10, 11
Energy Recovery
Sensible Effectiveness
User Defined
Heat exchanger sensible effectiveness at design heating and cooling conditions
3, 4, 9, 10, 11, 12
Latent Effectiveness
User Defined
Heat exchanger latent effectiveness at design heating and cooling conditions
3, 4, 9, 10, 11, 12
Economizer Bypass
User Defined
If ERV is bypassed during economizer conditions
3, 4, 9, 10, 11, 12
Energy Recovery Temp Control
User Defined
If bypass, target supply air temperature
3, 4, 9, 10, 11, 12
Fan Power Reduction during Bypass (W/cfm)
User Defined
If ERV system include bypass, static pressure setpoint and variable speed fan, fan power can be reduced during economizer conditions
3, 4, 9, 10, 11, 12
Demand Controlled Ventilation
DCV Application
User Defined
Percent of block floor area under DCV control
3, 4, 9, 10, 11, 12
DOAS
DOAS Fan Power W/cfm
User Defined
Fan input power in W/cfm of supply airflowa
12
DOAS Supplemental Heating and Cooling
User Defined
Heating source, cooling source
12
DOAS Supply Air Temperature Control
User Defined
SAT setpoint if DOAS includes supplemental heating or cooling and active temperature controls
12
Heating Plant
Boiler Efficiencyd
User Defined
Boiler thermal efficiency
1, 6, 7, 9, 10, 11, 12
Heating Water Pump Power (W/gpm)
User Defined
Pump input W/gpm heating water flow
1, 6, 7, 9, 10, 11, 12
Heating Water Loop Temperature
Fixed
180°F supply, 130°F return
1, 6, 9, 10,11
Chilled Water Plant
Chiller Compressor Type
User Defined
Screw/scroll, centrifugal or reciprocating
6,10, 11, 12
Chiller Condenser Type
User Defined
Air cooled or water cooled
6, 10, 11, 12
Chiller Full Load Efficiencyd
User Defined
Chiller COP
6, 10, 11, 12
Chilled Water Loop Configuration
User Defined
Variable flow primary only, constant flow primary - variable flow secondary
6, 10, 11, 12
Chilled Water Pump Power (W/gpm)
User Defined
Pump input W/gpm chilled water flow
6, 10, 11, 12
Chilled Water Temperature Reset Included
User Defined
Yes/No
6, 10, 11, 12
Chilled Water Temperature Reset Schedule (if included)
Fixed
Outdoor air reset: CHW supply temperature of 44°F at 80°F outdoor air dry-bulb and above, CHW supply temperature of 54°F at 60°F outdoor air dry-bulb temperature and below, ramped linearly between
6, 10, 11, 12
Condenser Water Pump Power (W/gpm)
User Defined
Pump input W/gpm condenser water flow
6, 7, 8, 9, 10, 11, 12
Condenser Water Pump Control
User Defined
Constant speed or variable speed
6, 7, 10, 11, 12
Cooling Tower Efficiency
User Defined
gpm/hp tower fan
6, 10, 11, 12
Cooling Tower
Cooling Tower Fan Control
User Defined
Constant or variable speed
6, 10, 11, 12
Cooling Tower Approach and Range
User Defined
Design cooling tower approach and range temperature
6, 10, 11, 12
Heat Pump Loop Flow Control
Loop Flow and Heat Pump Control Valve
Fixed
Two position valve with VFD on pump. Loop flow at 3 gpm/ton
7, 8
Heat Pump Loop Temperature Control
 
Fixed
Set to maintain temperature between 50°F and 70°F
7
GLHP Well Field
 
Fixed
Bore depth = 250 feet
Bore length 200 feet/ton for greater of cooling or heating load
Bore spacing = 15 feet
Bore diameter = 5 inches
3/4 inch Polyethylene pipe
Ground and grout conductivity = 4.8 Btu-in/h-ft2-°F
8
a Where multiple fan systems serve a single block, fan power is based on weighted average using on supply air cfm.
b Where multiple cooling systems serve a single block, COP is based on a weighted average using cooling capacity.
c Where multiple heating systems serve a single block, thermal efficiency or heating COP is based on a weighted average using heating capacity.
d Where multiple boilers or chillers serve a heating water or chilled water loop, efficiency is based on a weighted average for using heating or cooling capacity.
D602 Simulation of the standard reference design. The standard reference design shall be configured and analyzed as specified in this section.
D602.1 Utility rates. Same as proposed.
D602.2 Blocks. Same as proposed.
D602.3 Thermal zoning. Same as proposed.
D602.4 Occupancy type, schedule, density, and heat gain. Same as proposed.
D602.5 Envelope components. Same as proposed.
D602.6 Lighting. Same as proposed.
D602.7 Miscellaneous equipment. Same as proposed.
D602.8 Elevators. Not modeled. Same as proposed.
D602.9 Service water heating equipment. Not modeled. Same as proposed.
D602.10 On-site renewable energy systems. Not modeled. Same as proposed.
D602.11 HVAC equipment. The standard reference design HVAC equipment consists of separate space conditioning systems and dedicated outside air systems as described in Table D602.11 for the appropriate building occupancies.
Table D602.11
Standard Reference Design HVAC Systems
Parameter
Building Type
Large Officea
Small Office and Librariesa
Retail
School
System Type
Water-source Heat Pump
Packaged air-source Heat Pump
Packaged air-source Heat Pump
Packaged air-source Heat Pump
Fan Controlb
Cycle on Load
Cycle on Load
Cycle on Load
Cycle on Load
Space Condition Fan Power (W/cfm)
0.528
0.528
0.522
0.528
Heating/Cooling Sizing Factorc
1.25/1.15
1.25/1.15
1.25/1.15
1.25/1.15
Supplemental Heating Availability
NA
<40°F
<40°F
<40°F
Modeled cooling COP (Net of Fan) d
4.46
3.83
4.25
3.83
Modeled heating COP (Net of Fan) d
4.61
3.81
3.57
3.81
Cooling Source
DX (Heat Pump)
DX (Heat Pump)
DX (Heat Pump)
DX (Heat Pump)
Heat Source
Heat Pump
Heat Pump
Heat Pump
Heat Pump
OSA Economizere
No
No
Yes
Yes
Occupied Ventilation Sourcef
DOAS
DOAS
DOAS
DOAS
DOAS Fan Power
(W/cfm of Outside Air)
0.819
0.819
0.730
0.742
DOAS Temperature Control g, h
Bypass
Wild
Bypass
Bypass
ERV Efficiency (Sensible Only)
70 percent
70 percent
70 percent
70 percent
WSHP Loop Heat Rejection
Cooling Toweri
NA
NA
NA
WSHP Loop Heat Source
Gas Boiler j
NA
NA
NA
WSHP Loop Temperature Controlk
50°F to 70°F
NA
NA
NA
WSHP Circulation Pump W/gpml
16
NA
NA
NA
WSHP Loop Pumping Controlm
HP Valves & Pump VSD
NA
NA
NA
a Offices less than 50,000 square feet use "Small Office" parameters; otherwise use "Large Office" parameters.
b Space conditioning system shall cycle on to meet heating and cooling setpoint schedules as specified in ASHRAE Standard 90.1 Normative Appendix C. One space conditioning system is modeled in each zone. Conditioning system fan operation is not necessary for ventilation delivery.
c The equipment capacities (i.e., system coil capacities) for the standard reference design building design shall be based on design day sizing runs and shall be oversized by 15 percent for cooling and 25 percent for heating.
d COPs shown are direct heating or cooling performance and do not include fan energy use. See ASHRAE 90.1 Appendix G (G3.1.2.1) for separation of fan from COP in packaged equipment for units where the efficiency rating includes fan energy (e.g., SEER, EER, HSPF, COP).
e Economizer on space conditioning systems shall be simulated when outdoor air conditions allow free cooling. Economizer high limit shall be based on differential dry-bulb control. DOAS system continues to operate during economizer mode.
f Airflow equal to the outside air ventilation requirements is supplied and exhausted through a separate DOAS system including a supply fan, exhaust fan and sensible only heat exchanger. No additional heating or cooling shall be provided by the DOAS. A single DOAS system will be provided for each block. The DOAS supply and return fans shall run whenever the HVAC system is scheduled to operate in accordance with ASHRAE 90.1 Normative Appendix C.
g "Wild" DOAS control indicates no active control of the supply air temperature leaving the DOAS system. Temperature will fluctuate based only on entering and leaving conditions and the effectiveness of ERV.
h "Bypass" DOAS control includes modulating dampers to bypass ERV with the intent to maintain supply air temperature at a maximum of 60°F when outside air is below 75°F. Once outside air is above 75°F, bypass dampers will be fully closed.
i Includes a single axial fan cooling tower with variable speed fans at 40.2 gpm/hp, sized for an approach of 10°F and a range of 10°F.
j Includes a single natural draft boiler with 80 percent Et.
k Loop boiler and heat rejection shall be controlled to maintain loop temperature entering heat pumps between 50°F and 70°F.
l Pump motor input power shall be 16 W/gpm.
m Loop flow shall be variable with variable speed drive pump and unit fluid flow shutoff at each heat pump when its compressor cycles off.
[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-80500, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-80500, filed 1/19/16, effective 7/1/16.]
Site Contents
Selected content listed in alphabetical order under each group