Planning UES Measures:Prescriptive Duct Sealing SF

Performance-based Duct Sealing SFPerformance-based Duct Sealing MH

Adam Hadley & Josh RushtonRegional Technical Forum

October 20, 2015

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Overview

Today, we are seeking a decision to approve the research strategies and updated savings for the following planning UES measures:• Prescriptive Duct Sealing SF• Performance-based Duct Sealing SF• Performance-based Duct Sealing MH

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Measure OverviewMeasure Developers RTF CAT (plus input from Bob Davis)CAT Review Adam Hadley and Josh RushtonTech Sub-Com Review NoR&E Sub-Com Review October 7, 2015Notes • Prescriptive Duct Sealing SF has an old “research

plan” that needs updating to a “research strategy”. It sunsets Dec 2015.

• Performance-based Duct Sealing SF is currently “under review” because it needs a research strategy. It sunsets Dec 2015.

• Performance-based Duct Sealing MH has a “research strategy” associated with heat pumps, but it needs one to estimate overall savings for the measure. It sunsets Nov 2015.

Prescriptive Duct Sealing SF – What is it?Measure specifications focus on how to repair and seal ducts• Houses qualify for the measure if they have ducts (or leaks) located in

unconditioned space (and if the ducts haven’t been sealed by a program before)

• All accessible ducts in unconditioned space must be repaired and sealed with approved materials– Insulation is not considered a barrier to accessibility

5 Performance-based Duct Sealing – What is it?

Measure specifications call for both:• Prescriptive duct sealing (same spec), AND• Use of pre- and post- Duct Leakage Testing:

• Ducts must start out leaky enough• Ducts must finish tight enough

Background on Performance-based Duct Sealing• In the beginning, leakage testing was expected to

– provide duct sealers instant feedback, leading to higher savings, and – provide programs a method of checking the quality of duct sealing work

• The Region has struggled with this measure– Duct testing and duct sealing take different skill sets and accomplish different things– Duct testing is difficult, can give misleading results, and is time-consuming– Duct testing equipment is expensive– Pre-leakage measurements can be impossible to verify

• Post-leakage measurements on their own don’t signify savings occurred

• Programs have been (cautiously) moving from “performance-based” duct sealing to “prescriptive”– Shift the focus from testing to duct repair and sealing

6 Savings Estimates: Prescriptive Duct Sealing for Single Family

Methodology• Current (adopted August 2013)

– Set equal to previous Performance-based Duct Sealing SF value• Calculated in SEEM92 using old calibration

• Proposed– Use PSE Duct Ninja Study (link) results

• Duct seal savings = 68 therms– Using results of linear fixed effects regression

model, with RTF-like measure interaction adjustments

» report shows 29 therms, which represents duct seal as last measure in

• Savings is, then, 12% of heating energy use– RBSA average Gas FAF Heating consumption in HZ

1 = 587 therms– This assumes PSE study houses are similar to HZ1

RBSA houses• Apply 12% savings to electric FAF and heat

pump houses using RBSA heating energy use data– HZ 2 and 3 combined because of sample sizes in

RBSA

Source: RBSA, weighted, filtered for zero's

Heating System TypeHeating Zone 1

Heating Zones 2 and 3

Gas FAF (therms/yr) 587 618Electric Zonal (kWh/yr) 7368 9617Electric FAF (kWh/yr) 9061 14825Heat Pump (kWh/yr) 6494 8920

Gas FAF 438 161Electric Zonal 161 48Electric FAF 55 20Heat Pump 167 32

Heating Energy Use Data

Count

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Savings Estimates:Performance-based Duct Sealing for Single Family

• Methodology– Current (adopted December 2014)• Calculated using SEEM96, with latest calibration and

measure interactions– Baseline leakage inputs per RBSA– Efficient-case leakage inputs per BPA program data

– Proposed• Set equal to proposed UES for Prescriptive Duct Sealing

SF (previous slide)

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Savings Estimates:Performance-based Duct Sealing for Manuf. Homes

• Methodology– Current (adopted November 2012)• Calculated in SEEM92 using old calibration

– Proposed• Set equal to Prescriptive Duct Sealing MH (Proven)

– Approved August 2015– Applies % savings from PSE and Avista prescriptive MH

program impact evaluations to RBSA heating energy consumption

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Prescriptive SFPSE Duct Ninja % Savings ᵡ RBSA

Heating Energy

Performance SFSet to same as Prescriptive SF

Performance MHPrescriptive MH Evaluated % Savings

applied to RBSA heating energy

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Prescriptive SFMeasure Life: 20 years

Current Cost: $538Source: Median cost from 866 SF duct

seal installs in ETO program 2006-2008Proposed Cost: $550

Source: $750 (performance SF) - $200 (assumed cost for testing in SF)

Performance SFMeasure Life: 20 years

Current and Proposed Cost: $750Source: SIW, Median cost from 2,363 performance-qualified installs in ETO

2012 program

Performance MHMeasure Life: 18 years

Current Cost: $418Source: Same as MH Prescriptive, based on UCONS MH duct seal program average cost

Proposed Cost: $543Source: $418 (prescriptive MH) + $125

(assumed cost for testing in MH)

All costs in 2006$’s

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Research Strategies (Summary)

• Measures share a common research strategy, except sample requirements are distinct for each measure

• Savings estimates need to match planned UES specs• Savings Estimation Methodology

1. Researcher: Estimate % heating energy savings from a billing analysis• For each set of measure specification

– Sample size of 750 for at least 2 programs

2. RTF CAT: Apply % heating energy savings to average heating energy use estimate for each heating zone and heating system type• May need an adjustment for measure interactions

• Also collect delivery verification data so results can be translated from study to proven UES

• R&E Subcommittee recommended RTF adopt research strategy with the following changes– Add caution about the difficulty of delivery verification

on performance-based duct sealing– Require results from two or more programs

R&E Subcommittee ReviewOctober 7, 2015Participants:- Josh Rushton- Bob Davis- Andie Baker- Greg Kelleher- Lauren Gage- Phillip Kelsven- Rachel Clark- Richard Cole- Tom Eckhart- Jim Perich-Anderson- Todd Blackman- Mohit Singh-Chhabra- Adam Hadley

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CAT Thoughts• Discussion:

– We have evidence to suggest the basic prescriptive requirements (i.e. duct sealing) can achieve significant savings

– We have no evidence from available studies to suggest savings are different between prescriptive and performance-based duct sealing

– Performance-based requirements are difficult to verify without getting into program specifications

• Recommendation:– Merge the existing “Prescriptive Duct Sealing” and “Performance-based

Duct Sealing” measures into one generic measure named “Duct Sealing”• Adopt the prescriptive specifications for the “Duct Sealing” measure

– Programs can add duct testing requirements to test optimal program design• The RTF could revisit disaggregating the measures when considering a

provisional measure (with a funded research plan) or proven measure (with data)

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Changes CAT would make to Research Strategy

• Remove reference to different measure types– Performance SF, Prescriptive SF would be

reduced to “Duct Sealing SF”– Performance MH would be removed from

Research Strategy• Existing Proven “Prescriptive Duct Sealing MH”

measure would be renamed “Duct Sealing MH”

• Clear statement allowing different measure specifications

14 Proposed Motion

“I _________ move the RTF• Adopt the Duct Sealing Research Strategy with CAT-recommended changes• De-activate Performance-based Single Family Duct Sealing and Performance-based

Manufactured Home Duct Sealing UES Measures• Rename existing “Prescriptive Duct Sealing SF” UES measure to “Duct Sealing SF”

– Set savings to 12% of RBSA heating energy use– Keep category as Planning– Set Status to Active– Set Sunset date to October 2018

• Rename existing “Prescriptive Duct Sealing MH” UES measure to “Duct Sealing MH”– Keep savings, category, status, and sunset date as previously adopted

OR

• Adopt the Duct Sealing Research Strategy, as is• Set savings for Performance-based Single Family Duct Sealing and Prescriptive Single

Family Duct Sealing to 12% of RBSA heating energy use• Approve proposed savings for Performance-based Manufactured Home Duct Sealing• Keep Category at Planning• Set Status to Active• Set Sunset date to October 2018

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Extra Slides

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Justification for Use of % Savings• PSE Study shows fairly consistent % Savings across Pre-Heating Energy Use.

– * Within bins with a reasonable number of homes, and– **Within the typical range of Pre-heating energy use we look at in UES estimation methods

From August 2015 presentation. Refers to PSE Study: Reichmuth, Howard. "Independent M&V Report Puget Sound Energy Manufactured Home Duct Sealing (MHDS) Program, Final." December 5, 2013. Prepared for Thomas Eckhart UCONS LLC.

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For energy savings, higher pressure leaks are more important than lower pressure leaks (assuming equal sized leak area)

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Links to Measure Specifications

• Prescriptive Duct Sealing in Single Family– http://www.bpa.gov/EE/Sectors/Residential/Docu

ments/Prescriptive_Duct_Sealing_Spec_4_1_2015_Final.pdf

• Performance-based Duct Sealing in Single Family– http://rtf.nwcouncil.org/measures/res/ResPerfor

manceDuctSealingSpec_v3_1.docx• Performance-based Duct Sealing in

Manufactured Homes– http://rtf.nwcouncil.org/measures/res/ResPerfor

manceDuctSealingSpec_v3_1.docx