Planning UES Measures:
Prescriptive Duct Sealing SF
Performance-based Duct Sealing SF
Performance-based Duct Sealing MH
Adam Hadley & Josh Rushton
Regional Technical Forum
October 20, 2015
2
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
3
Measure Overview
Measure Developers
RTF CAT (plus input from Bob Davis)
CAT Review
Adam Hadley and Josh Rushton
Tech Sub-Com Review
No
R&E Sub-Com Review
October 7, 2015
Notes
•
•
•
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.
4
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
Savings Estimates:
6
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
Heating
Heating System Type
Zone 1
Zones 2 and 3
Heating Energy Use Data
Gas FAF (therms/yr)
587
618
Electric Zonal (kWh/yr)
7368
9617
Electric FAF (kWh/yr)
9061
14825
Heat Pump (kWh/yr)
6494
8920
Count
Gas FAF
438
161
Electric Zonal
161
48
Electric FAF
55
20
Heat Pump
167
32
7
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)
8
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
9
Prescriptive SF
PSE Duct Ninja % Savings ᵡ RBSA
Heating Energy
Performance SF
Set to same as Prescriptive SF

Performance MH
Prescriptive MH Evaluated % Savings
applied to RBSA heating energy
All costs in 2006$’s
10
Prescriptive SF
Measure Life: 20 years
Current Cost: $538
Performance SF
Measure Life: 20 years
Current and Proposed Cost: $750
Performance MH
Measure Life: 18 years
Current Cost: $418
Source: Median cost from 866 SF duct
seal installs in ETO program 2006-2008
Source: SIW, Median cost from 2,363
performance-qualified installs in ETO
2012 program
Source: Same as MH Prescriptive, based on
UCONS MH duct seal program average cost
Proposed Cost: $550
Source: $750 (performance SF) - $200
(assumed cost for testing in SF)
Proposed Cost: $543
Source: $418 (prescriptive MH) + $125
(assumed cost for testing in MH)
11
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
Review
October 7, 2015
Participants:
- 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
12
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 “Performancebased 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)
13
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
Proposed Motion
14
“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
15
Extra Slides
From August 2015 presentation. Refers to PSE Study: Reichmuth, Howard. "Independent M&V Report Puget Sound Energy Manufactured Home Duct Sealing
16 Program, Final." December 5, 2013. Prepared for Thomas Eckhart UCONS LLC.
(MHDS)
•
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
17
For energy savings,
higher pressure leaks
are more important
than lower pressure
leaks (assuming equal
sized leak area)
18
Links to Measure Specifications
• Prescriptive Duct Sealing in Single Family
– http://www.bpa.gov/EE/Sectors/Residential/Docume
nts/Prescriptive_Duct_Sealing_Spec_4_1_2015_Final.
pdf
• Performance-based Duct Sealing in Single Family
– http://rtf.nwcouncil.org/measures/res/ResPerformanc
eDuctSealingSpec_v3_1.docx
• Performance-based Duct Sealing in Manufactured
Homes
– http://rtf.nwcouncil.org/measures/res/ResPerformanc
eDuctSealingSpec_v3_1.docx