1

Proposed Revision to Energy Star New Homes Deemed

Savings

September 19, 2008

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

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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

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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

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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

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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

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CurrentRevised

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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

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Current Revised

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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

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Current Revised

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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

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CurrentRevised

*Reflects revised control assumptions, does not include lighting, DHW or dishwasher