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Washington Residential Energy Code 2012: Overview

17 December 2013

Ben Larson, Ecotope

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Code History and Overview• WA Energy Code updated on three year cycle. Previous code was

2009. Current is 2012. Effective 1 July 2013.– http://www.energy.wsu.edu/BuildingEfficiency/EnergyCode.aspx

• Code format changed from WA own to layout of IECC. Most provisions from previous codes retained.

• Energy codes set the new construction baseline for most efficiency measures

• Presentation Overview:– Code Description and Provisions– Compliance Options– Energy Use and Savings– Setting the baseline for efficiency measures

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Envelope

• Climate Zones now follow IECC designation. All counties in WA are 4M or 5 except for four counties in the north east:– Okanogan, Ferry, Stevens, Pend Oreille are IECC Zone 6

• Of those, only Ferry is the PNW Heating Zone 3, the rest are HZ 2

• Overall, little change in the base envelope requirements from 2009. Climate zone reassignment may have slightly relaxed the wall insulation requirement for the formerly WA Zone 2 locations

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Ducts, Infiltration, Lighting2009 2012

Duct Leakage - tested 6 cfm per 100ft2 of floor area at 25Pa

4 cfm per 100ft2 of floor area at 25Pa

House Leakage – tested SLA of 0.0003 (~5.5-6ACH50)

5ACH50

Lighting 50% High efficacy 75% High efficacy lamps

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Additional Requirements• Meet all of the prescriptive requirements and then obtain 1 point in 2009

and 1.5 points in 2012 from the following options:

2009 2012Option Description Points Option Description Points

1a HVAC: 92 AFUE or 8.5 HSPF 1 1a envelope a 0.51b ground source heat pump 2 1b envelope b 11c dhp 1 1c envelope c 22 ducts inside 1 2a exhaust fan 0.5

3a envelope a 0.5 2b hrv b 13b envelope b 1 2c hrv c 1.53c envelope c 2 3a 95 AFUE (gas only) 0.54a hrv a 0.5 3b 8.5 HSPF (hp only) 14b hrv b 1 3c ground source heat pump 25a dhw low flow & better tank 0.5 3d dhp (zonal only) 15b dhw low flow & hpwh or gas tankless 1.5 4 ducts inside 16 small dwelling 1 5a dhw low flow & better tank 0.57 large dwelling -1 5b dhw hpwh or gas tankless 1.58 renewables onsite 0.5 6 renewables onsite 0.5

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Which Options Are Selected?

• This is a common problem – it exists for the OR code, the previous WA code, and for EnergyStar in the Northwest.

• There is no certain answer to the question because any answer is a prediction.

• A possible approach:– estimate builder option selection based on cost and current market

saturations of heating systems, foundation types, and house sizes

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WA Energy Code 2012 vs 2009

House Size Heating System

Options Combinations

Electric Savings Gas Savings

Total Energy Savings

Incremental Cost

Options Weighting

kWh/yr/house therms/yr/house

BL1 DB1

Medium Size House

– needs 1.5

pts (83% of

population)

Gas Furnace No Cooling

gfnc_1a_2a_5a 861 58 11.6% $ 1,595 0.05 0.075gfnc_3a_1a_2a 861 51 10.7% $ 1,826 0.05 0.05gfnc_3a_1a_5a 394 83 12.9% $ 1,313 0.2 0.125gfnc_3a_2a_5a 861 41 9.4% $ 743 0.3 0.25gfnc_1a_2b___ 376 71 11.2% $ 3,253 0 0.025gfnc_1a_4____ 393 57 9.4% $ 1,383 0 0.025gfnc_1b_2a___ 861 76 14.1% $ 3,314 0 0.025gfnc_1b_5a___ 389 108 16.3% $ 2,801 0 0.025gfnc_2a_4____ 861 14 5.8% $ 813 0.1 0.05gfnc_3a_4____ 397 40 7.2% $ 530 0.1 0.1gfnc_4__5a___ 397 46 8.0% $ 300 0.1 0.15gfnc_5b______ 398 77 12.1% $ 716 0.1 0.1

Gas Furnace with CAC

gfac_1a_2a_5a 832 57 11.2% $ 1,595 0.05 0.075gfac_3a_1a_2a 832 50 10.3% $ 1,826 0.05 0.05gfac_3a_1a_5a 377 82 12.5% $ 1,313 0.2 0.125gfac_3a_2a_5a 868 41 9.2% $ 743 0.3 0.25gfac_1a_2b___ 305 70 10.5% $ 3,253 0 0.025gfac_1a_4____ 393 55 9.0% $ 1,383 0 0.025gfac_1b_2a___ 799 75 13.4% $ 3,314 0 0.025gfac_1b_5a___ 338 107 15.6% $ 2,801 0 0.025gfac_2a_4____ 884 13 5.7% $ 813 0.1 0.05gfac_3a_4____ 431 40 7.1% $ 530 0.1 0.1gfac_4__5a___ 431 46 7.9% $ 300 0.1 0.15gfac_5b______ 417 77 11.9% $ 716 0.1 0.1

Heat Pumphp85_3b_5a___ 1054 0 7.6% $ 77 0.7 0.7hp77_2a_4____ 850 0 6.1% $ 813 0.1 0.1hp77_4__5a___ 1025 0 7.4% $ 377 0.2 0.2

Zonal Resistance Heat

zonl_1b_2a___ 239 0 1.7% $ 513 0.5 0.4zonl_1b_5a___ 832 0 6.0% $ 77 0.5 0.5zonl_2a_3d___ 1433 0 10.2% $ 3,313 0 0.05zonl_3d_5a___ 1985 0 14.1% $ 2,877 0 0.05

Small House – needs 0.5

pts (15% of

population)

Gas Furnace No Cooling

gfnc_3a______ 679 43 12.4% $ 230 0.5 0.5gfnc_5a______ 679 49 13.6% $ - 0.5 0.5

Gas Furnace with CAC

gfac_3a______ 672 43 12.0% $ 230 0.5 0.5gfac_5a______ 672 49 13.2% $ - 0.5 0.5

Heat Pumphp77_2a______ 728 0 6.9% $ 327 0.2 0.2hp85_3b______ 868 0 8.2% $ - 0.4 0.4hp77_5a______ 951 0 9.0% $ 77 0.4 0.4

Zonal Resistance Heat

zonl_2a______ 135 0 1.3% $ 327 0.2 0.2zonl_5a______ 671 0 6.3% $ 77 0.8 0.8

Overall kWh/yr/house Savings 681 669Overall therms/yr/house Savings 42 44

Overall Total Energy Percent Savings 9.6% 9.8%Overall Cost $ 678 $ 790

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WA Code Over the Years

2006 2009 2012 2015 20180%

10%20%30%40%50%60%70%80%90%

100%Residential Energy Code Savings by Year

Code Year

Ener

gy U

se R

elati

ve to

200

6 Co

de

Target: 70% reduction in building energy use by 2031 per WA SB 5854

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What about Conservation Measures?

• New construction house characteristics (baseline) can now differ between houses

• Scenario 1a: Ducts inside– Baseline house has Options 4 (ducts inside) and 5a (low flow fixtures)

• A ducts inside efficiency measure has zero savings compared to this baseline

• Scenario 1b: Ducts inside – Baseline house has Options 3b (heat pump upgrade) and 5a (low flow fixtures)

• Adding ducts inside to this baseline house does produce energy savings

• Scenario 2: Upgraded Heat Pump to HSPF 9.0– Baseline house has Options 3b (heat pump upgrade to HSPF 8.5) and 5a (low flow

fixtures)• The savings from the measure is the difference between an HSPF 8.5 and 9.0 heat pump

Savings from any individual new construction efficiency measure is not guaranteed.

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What is the Best Baseline?

• For a given measure, the baseline changes and depends on what code path was selected.– HSPF 9.0 measure would have an HSPF 8.5

baseline.– Ducts inside measure has a ducts inside baseline

(mostly)• To get reliable savings from measures in WA

for new construction, they will need to be bundled and packaged up

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Existing Measure Package Examples

• EnergyStar• Montana House• BuiltGreen• Eco-Rated and High Performance

Manufactured Homes

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Conclusion and Recommendations

• WA Residential Code improved 9-10% over 2009• Individual measures are challenged, including:

– Heat pump upgrades, interior ducts, efficient DHW tanks, HPWHs, and showerheads

– These UES measures need to be reexamined under the new baseline• Recommend avoiding individual measures in new construction

in favor of packages• Existing EnergyStar needs revamp for WA• Other, additional packages can be created• Picking additional items off the options list can also form the

basis of a conservation measure (scenario 1b)

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Additional Slides Follow

Ben LarsonEcotopeben@ecotope.com206.322.3753

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Washington Code Options Table

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