1 Air Source Heat Pumps Potential Changes in the RTF’s Specifications & Savings Estimates and...
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1
Air Source Heat Pumps
Potential Changes in the RTF’s Specifications & Savings Estimates and Their Impact on C&R Discount
Program Credits
2
Why “Things” Are Changing – New Energy Star Specifications
• Energy Star labeled air source heat pumps established new performance criteria effective October 1, 2002– Split System Minimums
• SEER – 13.0
• HSPF - 8.0
• EER – 11.0
– Package System Minimums• SEER – 12.0
• HSPF – 7.6
• EER – 10.5
3
Why “Things” Are Changing – PNW Climates Are Different
• ARI performance ratings (SEER & HSPF) are based on climates that do not match the Northwest’s.– Heating Zone 1 climate is warmer than the rating
location – HSPF is higher than label– Heating Zones 2 & 3 climates are colder than the
rating location – HSPF is lower than label– All of the Cooling Zones in NW has lower humidity
than the rating location – SEER is lower than label
4
Climate Adjusted HSPF
104%105% 92% 91% 89%
0%
20%
40%
60%
80%
100%
Per
cent
of
AR
I R
atin
g
Portland Seattle Boise Spokane Missoula
5
Why Things Are Changing – Control Practices Reduce Performance
• Set-Back Thermostats (with or without “ramp up” features) often result in use of electric resistance heat
• Timed-defrost controls (particularly in Heating Zones 2 & 3) operate even when relative humidity is too low to produce icing
• Compressor “cut-out” temperatures are set too high, so compressor doesn’t operate even when it has a COP above 1.0.
6
Control Adjusted HSPF
94%97%
68% 65%62%
0%
20%
40%
60%
80%
100%
Per
cent
of
AR
I R
atin
g
Portland Seattle Boise Spokane Missoula
7
Why Things Are Changing - Failure to Properly Commission Heat Pumps
• Field studies of heat pump and air conditioner installations reveal– Over/Under Charging of Refrigerant– Low air flow across evaporator coils
8
Commissioning Adjusted HSPF
94% 94%82% 82% 79%
0%
20%
40%
60%
80%
100%
Per
cent
of
Rat
ed H
SPF
Portland Seattle Boise Spokane Missoula
9
Cumulative Adjusted HSPF
85% 88%
60% 59% 56%
0%
20%
40%
60%
80%
100%
Per
cent
of
Rat
ed H
SPF
Portland Seattle Boise Spokane Missoula
10
SEER Doesn’t Match Label Either
• High performance air conditioning equipment is designed to “de-humidify” by recovering latent energy (heat of condensation)
• Preliminary research appears to show that SEER ratings, when adjusted for the PNW “dry-summer” climate are about 65% of nameplate
– Nominal 10 SEER => Real 6.5 SEERNominal 10 SEER => Real 6.5 SEER
11
Other Factors That Are Changing RTF’s Heat Pump Savings
• Revised estimates of “post-weatherization” space heating use– Reduced loads
• Revised estimate of air conditioning loads– New estimates based on hourly modeling of specific
prototypes
• Better calibration with metering studies for space heating and cooling
12
Pre1980 Construction “Post Weatherization” Forced Air Furnace Space Heating Use
0
5,000
10,000
15,000
20,000
25,000
Zone 1 Zone 2 Zone 3
Ann
ual U
se (
kWh)
Original Estimate Revised Estimate
13
Post79/Pre93 Construction Forced Air Furnace Space Heating Use
0
5,000
10,000
15,000
20,000
25,000
30,000
Zone 1 Zone 2 Zone 3
Ann
ual U
se (
kWh)
Original Estimate Revised Estimate
14
Post92 Construction Forced Air Furnace Space Heating Use
0
5000
10000
15000
20000
25000
Zone 1 Zone 2 Zone 3
Ann
ual U
se (
kWh)
Original Estimate Revised Estimate
15
Revised Estimates of Air Conditioning Loads Are
Lower (e.g.,Pre1980 Construction)
0
500
1,000
1,500
2,000
2,500
3,000
3,500
Portland Seattle Boise Spokane Missoula
Original Space Cooling Load (kWh/yr) Revised Space Cooling Load (kWh/yr)
16
Revised Estimates of Air Conditioning Load Are
Lower (e.g., Post92 Construction)
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
Portland Seattle Boise Spokane Missoula
Original Space Cooling Load (kWh/yr) Revised Space Cooling Load (kWh/yr)
17
However, Some Revised Estimates of Air Conditioning Load Are
Higher and Lower (e.g.,Post79/Pre93 Construction)
0500
1,0001,5002,0002,5003,0003,5004,0004,500
Portland Seattle Boise Spokane Missoula
Original Space Cooling Load (kWh/yr) Revised Space Cooling Load (kWh/yr)
18
Overall Implications for C&R Discount Values
• Difference Between “PTCS” Heat Pump (or CAC) Installations & Non-“PTCS” Installations Increases
• Difference between Non-PTCS Heat Pump (or CAC) Installations and “Baseline” Installations Decreases
19
Air Source Heat Savings Adjustments for Pre1980 FAF w/o CAC – “Worst Case”
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current with PTCS Revised with PTCS
20
Air Source Heat Savings Adjustments for Post79/Pre93 FAF w/o CAC – “Worst Case”
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current with PTCS Revised with PTCS
21
Air Source Heat Savings Adjustments for Post1992 FAF w/o CAC – “Worst Case”
0
2,000
4,000
6,000
8,000
10,000
12,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current with PTCS Revised with PTCS
22
Air Source Heat Savings Adjustments for Pre1980 FAF w/o CAC – “Worst Case”
0
2,000
4,000
6,000
8,000
10,000
12,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current without PTCS Revised without PTCS
23
Air Source Heat Savings Adjustments for Post79/Pre93 FAF w/o CAC – “Worst Case”
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current without PTCS Revised without PTCS
24
Air Source Heat Savings Adjustments for Post1992 FAF w/o CAC – “Worst Case”
01,0002,0003,0004,0005,0006,0007,0008,0009,000
10,000
Heating 1Cooling 1
Heating 1Cooling 2
Heating 1Cooling 3
Heating 2Cooling 1
Heating 2Cooling 2
Heating 2Cooling 3
Heating 3Cooling 1
Heating 3Cooling 2
Heating 3Cooling 3
Ann
ual S
avin
gs (
kWh)
Current without PTCS Revised without PTCS
Example 1 – Pre80 Single Family w/Furnace in Heating & Cooling Zone 1
Case Annual Savings (kWh)
C&R Discount Credit ($)
Current w/o PTCS 6,839 $ 2,241
Current w/PTCS 8,055 $ 2,661
Proposed w/o PTCS 4,298 $ 1,407
Proposed w/PTCS 6,484 $ 2,155
Example 2 – Post79/Pre93 Single Family w/Furnace in Heating Zone 1 & Cooling Zone 2
Case Annual Savings (kWh)
C&R Discount Credit ($)
Current w/o PTCS 8,971 $ 3,036
Current w/PTCS 10,308 $ 3,496
Proposed w/o PTCS 7,386 $ 2,514
Proposed w/PTCS 10,733 $ 3,673
Example 3 – Post92 Single Family w/Zonal Heat & No CAC in Heating Zone 1 & Cooling Zone 3
Case Annual Savings (kWh)
C&R Discount Credit ($)
Current w/o PTCS 2,944 $ 744
Current w/PTCS 4,045 $ 1,153
Proposed w/o PTCS 631 $ (136)
Proposed w/PTCS 2,906 $ 699
Example 4 – Pre80 Single Family w/Furnace & w/o CAC in Heating & Cooling Zone 2
Case Annual Savings (kWh)
C&R Discount Credit ($)
Current w/o PTCS 9,633 $ 3,119
Current w/PTCS 11,178 $ 3,651
Proposed w/o PTCS 5,073 $ 1,601
Proposed w/PTCS 8,425 $ 2,739
29
RTF Estimates Compared to City of Richland’s Analysis
City of Richland
Original w/PTCS
Revised w/PTCS
Original w/o PTCS
Revised w/o PTCS
House Size 2,071 – 2,136
1,600
1,600
1,600
1,600
Savings (kWh/yr) 5,552 –6,706
8,560
6,444
7,532
4,495
Savings/Ton (kWh/yr)
1,828 - 2,154
2,853
2,148
2,511
1,498
Savings/sq.ft./ floor area
2.7 – 3.1
5.3
4.0
4.7
2.8
30
RTF Estimates Compared to City of Richland’s Analysis
City of Richland
Original w/PTCS
Revised w/PTCS
Original w/o PTCS
Revised w/o PTCS
CAC Use - (1,020) (1,254) (1,226) (1,845)
Net Savings (kWh/yr)
5,552
7,540
5,190
6,307
2,650
Net Savings/sq.ft.
2.7
4.7
3.2
3.9
1.7
Just One More Thing . . .
Any Questions?
Comments?
32
The Impact of Climate on HSPF
01
2345
6789
Cli
mat
e A
djus
ted
HSP
F
Portland Seattle Boise Spokane Missoula
Rated HSPF = 7.1 Rated HSPF = 8.0
33
The Impact of Controls on HSPF
0
1
2
3
4
5
6
7
8
Con
trol
Adj
uste
d H
SPF
Portland Seattle Boise Spokane Missoula
Rated HSPF = 7.1 Rated HSPF = 8.0
34
Impact of Improper Commissioning on HSPF
0
1
2
3
4
5
6
7
8
Com
mis
sion
ing
Adj
uste
d H
SPF
Portland Seattle Boise Spokane Missoula
Rated HSPF = 7.1 Rated HSPF = 8.0
35
Cumulative Impact on HSPF
0
1
2
3
4
5
6
7
Cum
ulat
ive
Adj
uste
d H
SPF
Portland Seattle Boise Spokane Missoula
Rated HSPF = 7.1 Rated HSPF = 8.0