B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Variable Capacity Heat Pump RTF Sub-Committee
October 26, 2011
Mira Vowles, P.E., CEM Emerging Technology Project Manager
BPA Energy Efficiency
Slide 1
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
PNW Small Office Baseline
Energy Use per SF
RTU Gas Furnace Energy Use per Square Foot
Cooling
(kWh/SF)
Heating
(Th/SF)
Seattle
0.7
0.0
6.4
7.2
Spokane
1.2
0.1
6.5
7.7
Fans
(kWh/SF)
Total HVAC (kWh/SF)
RTU Heat Pump Energy Use per Square Foot
Cooling (kWh)
Heating (kWh)
Fans (kWh)
Total (kWh)
Seattle
0.7
0.6
6.4
7.7
Spokane
1.2
1.8
6.5
9.5
Based on EnergyPro model for PNW locations
Slide 2
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
PNW Small Office VC HP
Energy Use per SF
VRF Heat Pump Energy Use per Square Foot
Cooling
(kWh/SF)
Heating
(kWh/SF)
Fans (kWh
/ SF)
Total HVAC (kWh/SF)
Seattle
1.2
0.7
0.7
2.7
Spokane
1.3
1.6
0.8
3.7
VRF Heat Recovery Energy Use per Square Foot
Cooling
(kWh/SF)
Heating
(kWh/SF)
Fans
(kWh/SF)
Branch Box
(kWh / SF)
Total HVAC
(kWh/SF)
Seattle
1.3
0.8
0.7
0.0
2.8
Spokane
1.4
1.7
0.8
0.0
4.0
Based on EnergyPro model for PNW locations
Slide 3
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Small Office VRF Savings Summary
Location (TMY)
Electric Savings
(kWh / SF)
Gas Heat Offset
(Therms / SF)
% HVAC Electric
Savings
Seattle
4.5
0.0
25%
Spokane
3.9
0.1
21%
Single zone RTU heat pump
replaced on burn-out to
VRF HP system
Seattle
5.0
28%
Single zone RTU heat pump
replaced on burn-out to
VRF HP system
Spokane
5.8
30%
Measure Description
Single zone RTU with gas heat
replaced on burn-out to
VRF HP system
Single zone RTU with gas heat
replaced on burn-out to
VRF HP system
Average
4.8
(kWh / SF)
26%
Slide 4
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
PNW Medium Office Energy Use
VRF Heat Pump
Cooling (kWh)
Heating (kWh)
Fans (kWh)
Total (kWh)
Seattle
52,759
17,252
22,320
92,331
Spokane
55,515
34,124
24,510
114,149
Cooling (kWh)
Heating (kWh)
Fans (kWh)
Branch Box (kWh)
VRF Heat Recovery
Total (kWh)
Seattle
53,069
9,439
22,320
1,956
86,784
Spokane
52,075
29,633
24,510
1,917
108,135
Cooling (kWh)
Heating (therms)
Fans (kWh)
Pumps (kWh)
Total (kWh)
Seattle
87,880
3,400
53,437
618
141,935
Spokane
89,446
4,938
61,871
902
152,219
Cooling (kWh)
Heating (kWh)
Fans (kWh)
Total (kWh)
Seattle
85,708
58,628
52,853
197,189
Spokane
86,970
84,725
60,665
232,360
VAV Gas Boiler Reheat
VAV Electric Reheat
Based on EnergyPro model for PNW locations
Slide 5
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
PNW Medium Office Baseline
Energy Use per SF
VAV Gas Boiler Reheat
Total HVAC (kWh/SF)
Cooling
(kWh/SF)
Heating
(Th/SF)
Fans
(kWh/SF)
Pumps
(kWh/SF)
Seattle
2.1
0.1
1.3
0.0
3.4
Spokane
2.2
0.1
1.5
0.0
3.7
Cooling
(kWh/SF)
Heating
(kWh/SF)
Fans
(kWh/SF)
Total HVAC
(kWh/SF)
Seattle
2.1
1.4
1.3
4.8
Spokane
2.1
2.0
1.5
5.6
VAV Electric Reheat
Based on EnergyPro model for PNW locations
Slide 6
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
PNW Medium Office VC HP
Energy Use per SF
VRF Heat Pump
Cooling
(kWh/SF)
Heating
(kWh/SF)
Fans (kWh
/ SF)
Total
HVAC
(kWh/SF)
Seattle
1.3
0.4
0.5
2.2
Spokane
1.3
0.8
0.6
2.8
Cooling
(kWh/SF)
Heating
(kWh/SF)
Fans
(kWh/SF)
Branch
Box (kWh
/ SF)
Total HVAC (kWh/SF)
Seattle
1.3
0.2
0.5
0.0
2.1
Spokane
1.3
0.7
0.6
0.0
2.6
VRF Heat Recovery
Based on EnergyPro model for PNW locations
Slide 7
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Medium Office VRF Savings Summary
Location (TMY)
Electric Savings
(kWh / SF)
Gas Heat Offset
(Therms / SF)
% HVAC Electric
Savings
Packaged VAV with gas boiler
replaced on burn-out to
VRF HP system
Seattle
1.2
0.1
35%
Packaged VAV with gas boiler
replaced on burn-out to
VRF HP system
Spokane
0.9
0.1
25%
Packaged VAV with elec reheat
replaced on burn-out to
VRF HP system
Seattle
2.5
53%
Packaged VAV with elec reheat
replaced on burn-out to
VRF HP system
Spokane
2.8
51%
Measure Description
Average
1.9
(kWh / SF)
41%
Slide 8
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Small Office VRF Cost Effectiveness
RF HP
asure #
B
Ince
(
Baseline System
Location
(TMY)
Incr. Cost
($ / ton)
BCR
SPB
(years)
1
Small Office ASHRAE
System #3 (Packaged single
zone AC with gas heat)
Seattle
835
3.1
8
$3
2
Small Office ASHRAE
System #3 (Packaged single
zone AC with gas heat)
Spokane
835
3.1
9
$2
3
Small Office ASHRAE
System #4 (Packaged single
zone heat pump)
Seattle
860
3.1
7
$3
4
Small Office ASHRAE
System #4 (Packaged single
zone heat pump)
Spokane
860
3.6
7
$4
BCR
3.2
Average
$3
per
Slide 9
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Medium Office VRF Savings Summary
VRF HP
Measure #
BP
Incen
($
Location
(TMY)
Incr. Cost
($ / ton)
BCR
SPB
(years)
5
Medium Office ASHRAE
System #5 (Packaged VAV
with gas boiler reheat)
Seattle
540
3.4
3
6
Medium Office ASHRAE
System #5 (Packaged VAV
with gas boiler reheat)
Spokane
540
2.6
3
7
Medium Office ASHRAE
System #6 (Packaged VAV
with electric reheat)
Seattle
540
4.8
5
$3
8
Medium Office ASHRAE
System #6 (Packaged VAV
with electric reheat)
Spokane
540
5.5
6
$3
Average
BCR
4.1
Baseline System
$1
$9
$2
per
Slide 10
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Proposed VRF Measures
VC HP
Measure #
Measure Description
Average
Electric
Savings
(kWh / ton)
1
Office Building VRF HP
system retrofit (< 80 tons
per building)
1,573
26%
2
Office Building VRF HP
system retrofit (>= 80
tons per building)
1,119
41%
Total Building
% Electric
Savings
Slide 11
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Variable Refrigerant Flow System Definition
Variable refrigerant flow (VRF) systems, either heat-pump
or heat-recovery styles, provide heating and airconditioning, and typically consist of:
1. An outdoor unit with inverter driven compressor(s) and
condenser fan, over 6 tons of capacity (72,000 Btu/h),
2. Multiple indoor units with multi-speed fans, electronic
expansion devices and dedicated microprocessors,
3. Refrigerant piping between the outdoor and indoor units,
4. A zone temperature control device interlocked with a
system controller.
Slide 12
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Office Building Definition
 A building used primarily for office functions, including
desk-work, reading and light equipment (computer,
copier, printer, telephone, etc.) use.
 Office occupancies are further defined by
 overall occupant densities between 50 and 300
square feet per person,
 overall lighting power densities between 0.5 and 2
watts per square foot, and
 overall equipment plug loads between 0.1 and 1.5
watts per square foot.
Slide 13
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
Office Building Definition
 Can whole building regression analysis be
used to verify savings?
 How many systems need to be evaluated?
 How can buildings with significant other
changes be excluded?
 Other?
Slide 14
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
VRF Program Evaluation Questions
 Can whole building regression analysis be
used to verify savings?
 How many systems need to be evaluated?
 How can buildings with significant other
changes be excluded?
 Other?
Slide 15
B O N N E V I L L E
P O W E R
A D M I N I S T R A T I O N
VRF Program Delivery Questions
 Can this be a utility equipment rebate
program, instead of an upstream program?
 Limit to replacement on burn-out?
 How to ensure replacement on burn-out?
 Limit to baseline systems?
 How to ensure baseline systems?
 Other?
Slide 16