1 proposed revision to energy star new homes deemed savings september 19, 2008
TRANSCRIPT
2
Background – Why Update Savings
• Current Savings Estimate Do Not Reflect Current Standards and Market Conditions– Heat Pump & CAC
• Current Baseline = HSPF 7.0/SEER 11• Revised Baseline = HSPF 7.7/SEER 13 (New federal standard)• Energy Star minimum = HSPF 8 (original) vs. HSPF 8.5 (new)
– Dishwasher• Current Baseline = EF-52 • Revised Baseline = EF-60 (AHAM 2004 sales weighted average EF)• Energy Star minimum = EF-58 (original) vs. EF-65 (new Energy Star spec)
– Windows• Current Baseline = Class 40• Revised Baseline = Class 35 (Based
3
Background – Why Update Savings
• Energy Star Lighting – Current estimates do not reflect “new construction” lighting power
densities
– Alternative Energy Star lighting “packages” not integrated into savings estimates
• Thermal shell baseline not consistent with revised energy codes
• Heat Pump “Control Mix” Do Not Reflect Results of Regional Heat Pump Evaluation– Current assumptions too pessimistic for “baseline”
– PTCS assumptions slightly pessimistic, but probably OK
4
Heat Pump Control Strategies
• Ideal Ideal - ARI controller from testing method• Comfort Assist Comfort Assist - First stage ER operates below 30º• Five Plus Five Plus - 5 kW first stage with the compressor, all
temperatures• Low Ambient Low Ambient - Compressor off below 30º, ER only• Outdoor Tstat Outdoor Tstat - Ideal controller with ER lockout above
40º
5
Current Assumed Control Weightings – Base Case
0%
20%
40%
60%
80%
100%
Base Case PTCS
Wei
ght
Comfort AssistLow Ambient CutoutPlus 5IdealOutdoor Tstat
6
Control Weightings
• RTF– 2003 calculation, used current EStar calculator and “deemed savings” values
• ETO—2005 weighting for Energy Trust of Oregon Resource assessment
• Estar Homes—2005 weighting used in EStar savings estimates for Alliance
• HP2005—Results of Heat Pump study
Alternative Control Weightings Impact on Heat Pump System Efficiency & Performance
Ideal RTF-Base ETO Estar Homes HP2005
ARI Controller 100% 0% 50% 10% 40%
Comfort Assist 60% 0% 0% 15%
Plus 5 20% 40% 30% 25%
Low-ambient cutout 20% 10% 60% 15%
Outdoor Tstat 0% 0% 0% 5%
Performance
Zone 1 4,451 5,176 5,435 5,440 5,117
86% 82% 82% 87%
Zones 2 & 3 9,206 11,803 10,773 12,322 10,587
78% 85% 75% 87%
8
Control System Assumption Impact on System Efficiency – Current Assumptions
75%
80%
85%
90%
95%
100%
Zone 1 Zone 2 Zone 3
Base - Crawl
PTCS - Crawl
Base - Half Bsmnt
PTCS - Half Bsmnt
Base - Full Bsmnt
PTCS - Full Bsmnt
9
Recommended Calculator Revisions
• Since Heat Pump now require Outdoor Tstat and set-up for ODT PTCS control assumptions should be revised to include “Ideal” controller and “Outdoor T” controller
• Base Case control assumptions should be adjusted to more closely reflect field observations
10
Recommended Revised Control Weightings
0%
20%
40%
60%
RTF Base PTCS
Wei
ght
Ideal ARI Controller
Comfort Assist
Five+
Low-ambient
Outdoor T
11
Revised Control System Assumption Impact on System Efficiency
75%
80%
85%
90%
95%
100%
105%
110%
115%
Zone 1 Zone 2 & Zone 3
RTF-Original
PTCS-Original
RTF-Revised
PTCS-Revised
12
New Home Lighting Power Densities Are Higher Than Currently Assumed
0.0
0.5
1.0
1.5
2.0
2.5
Total House LPD Hardwired LPD
Wat
ts/S
q F
t
Overall
Single Family - Detached- 1 story
Single Family - Detached- 2 story
Single Family - Detached- 3 or more story
Townhome/Rowhouse
Current LPD Assumption
Source: NEEA New Construction Survey
13
New Homes Have Double the Currently Assumed Number of “Sockets”
0102030405060708090
All LampsTypes
CFLs Non-CFLFlourescent
Total
Halogen Total IncandescentTotal
Lam
ps
Source:NEEA New Construction Survey
Current Assumption
CALMAC Results = No Correlation Between House Size & Average Hrs of Lighting Use
Source: CFL Metering Study – Final Report. Prepared for Pacific Gas & Electric Company, San Diego Gas & Electric Company and Southern California Edison by KEMA, Inc. February 25, 2005
15
Proposed Revised Energy Star Lighting Savings Assumptions
• Current Assumptions – 15 CFLs installed per home operating 2.67 hrs/day
• Proposed Revised Assumptions (and specifications)– Energy Star Lighting Package 1 (minimum) = 30 CFLs– Energy Star Lighting Package 2 = 45 CFLs*– Energy Star Lighting Package 3 = 54 CFLs**– All packages assumed to operate 2.0 hrs/day
*or maximum hardwired LPD of 0.8 Watts/sq ft** or maximum hardwired LPD of 0.6 Watts/sq ft
16
Proposed Revised Energy Star Deemed Savings for Lighting Packages
0200400600800
1,0001,2001,4001,6001,8002,000
Zonal w/o AC Heat Pump Gas FAF w/AC
An
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gs (
kW
h)
Package 1
Package 2
Package 3
Current Baseline Thermal Shell Assumptions
Component Zone 1 Zone 2 Zone 3
Attic 0.030 0.030 0.030
Door 0.187 0.187 0.187
Floor 0.029 0.029 0.029
Infiltration 0.35 0.35 0.35
Joisted Vault 0.034 0.034 0.034
Slab-on-Grade (F-Value/lin.ft. perimeter) 0.52 0.52 0.52
Trussed Vault 0.039 0.039 0.039
Wall 0.058 0.058 0.058
Wall Below Grade (Interior) 0.037 0.037 0.037
Slab-below-Grade (F-Value/lin.ft. perimeter) 0.57 0.57 0.57
Window 0.388 0.388 0.388
Proposed Revised Baseline Thermal Shell Assumptions – Alternative 1 (code)
Component Zone 1 Zone 2 Zone 3
Attic 0.031 0.031 0.025
Door 0.187 0.187 0.187
Floor 0.031 0.030 0.035
Infiltration 0.35 0.35 0.35
Joisted Vault 0.034 0.034 0.034
Slab-on-Grade (F-Value/lin.ft. perimeter) 0.52 0.52 0.52
Trussed Vault 0.039 0.039 0.039
Wall 0.062 0.062 0.061
Wall Below Grade (Interior) 0.037 0.037 0.037
Slab-below-Grade (F-Value/lin.ft. perimeter) 0.57 0.57 0.57
Window 0.34 0.34 0.34
Proposed Revised Baseline Thermal Shell Assumptions – Alternative 2 (Current Practice)
Component Zone 1 Zone 2 Zone 3
Attic 0.028 0.029 0.026
Door 0.187 0.187 0.187
Floor 0.040 0.041 0.065
Infiltration 0.35 0.35 0.35
Joisted Vault 0.034 0.034 0.034
Slab-on-Grade (F-Value/lin.ft. perimeter) 0.52 0.52 0.52
Trussed Vault 0.039 0.039 0.039
Wall 0.065 0.066 0.063
Wall Below Grade (Interior) 0.037 0.037 0.037
Slab-below-Grade (F-Value/lin.ft. perimeter) 0.57 0.57 0.57
Window 0.437 0.462 0.402
20
Estimated Energy Star Home Deemed Savings Using Alternative Thermal Shell Assumptions
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
Zone 1 Zone 2 Zone 3
An
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gs (
kW
h) Zonal - Code Base
Zonal-Current PracticeBase
HP-Code Base
HP-Currrent Practice Base
21
Proposed Thermal Shell Revisions
• Alternative 1– Uses code as baseline, avoids paying incentives to
“meet” code– Does not reflect actual building practice
• Alternative 2 – Reflects actual incremental improvement in thermal
shell, hence savings– Does not appear to reflect current market share of
Energy Star windows
22
Current and Revised Energy Star Homes Deemed Savings - Zonal
0
1000
2000
3000
4000
5000
6000
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
An
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kW
h)
CurrentRevised
23
Current and Revised Energy Star Homes Deemed Savings – Gas Furnace w/o CAC
0
200
400
600
800
1000
1200
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
An
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kW
h)
Current Revised
24
Current and Revised Energy Star Homes Deemed Savings – Gas Furnace w/ CAC
0
200
400
600
800
1000
1200
1400
1600
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
An
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kW
h)
Current Revised
25
Energy Star Homes Revised Deemed Savings Relative to Existing Deemed Savings - Crawlspace
0%
20%
40%
60%
80%
100%
120%
140%
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
Zonal Heat Pump Gas FAF w/o CAC Gas FAF w/ CAC
26
Energy Star Homes Revised Deemed Savings Relative to Existing Deemed Savings – Half Basement
0%
20%
40%
60%
80%
100%
120%
140%
160%
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
Zonal Heat Pump Gas FAF w/o CAC Gas FAF w/ CAC
27
Energy Star Homes Revised Deemed Savings Relative to Existing Deemed Savings – Full Basement
0%
20%
40%
60%
80%
100%
120%
140%
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
Zonal Heat Pump Gas FAF w/o CAC Gas FAF w/ CAC
28
Current and Revised Energy Star Homes Deemed Savings – Heat Pump*
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
Heat 1 -Cool 1
Heat 1 -Cool 2
Heat 1 -Cool 3
Heat 2 -Cool 1
Heat 2 -Cool 2
Heat 2 -Cool 3
Heat 3 -Cool 1
Heat 3 -Cool 2
Heat 3 -Cool 3
An
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usb
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gs (
kW
h/y
r)
CurrentRevised
*Reflects revised control assumptions, does not include lighting, DHW or dishwasher