1. Prescriptive Duct Sealing UES Measure Proposal Regional Technical Forum Subcommittee July 8, 2013

2. Overview BPA is proposing a new “Prescriptive Duct Sealing” measure – This measure does not replace the “PTCS Duct Sealing” measures. Proposed UES Measure Category: Planning – The Guidelines require: UES Estimation: Baseline and Efficient-case can be estimated Research Plan to bring measure to Provisional or Proven category Goal for the Subcommittee: – Review the measure proposal in detail for compliance with the guidelines. Provide feedback to BPA and SBW for improvements. Three primary components for review according to guidelines: – Measure Specifications – UES estimation method and input assumptions – Research Plan (this is being proposed as a provisional measure) – Consensus on the subcommittee’s recommendation to the RTF regarding the measure (Adoption? Edits? Options to consider?) 2

3. Measure Specification Summary Applies to existing single family or existing manufactured homes Measures for four heating systems – eFAF w/CAC – eFAF w/o CAC – Heat Pump – Average (any of the three above) Site Qualification – 30% or more of supply ducts in accessible unconditioned space Exception for high pressure leaks, new duct systems; clarification on conditioned space; clarification on accessibility of ducts; no previous PTCS sealing Duct Repair and Support Sealing Requirements – Accessible portions must be sealed Description of sealing that must take place Replacement of removed insulation CO alarm required in houses with Combustion Appliance 3 Note: This is a summary. See the Specification for more details.Specification

4. UES Estimation Method Summary Use the same methodology (and savings) as the existing PTCS UES measures SEEM Simulation – Constant Parameters Fully Weatherized House 12% of homes have 0 savings – Primary Parameters Supply Duct Leakage (% of Air Handler Flow) – Baseline SF: 15%MH: ~20% – Efficient-CaseSF: 5%MH: ~6% These primary parameters will be updated once data collection as per research plan is complete. 4 Note: This is a summary. See the Summary Sheet for more details.Summary Sheet

5. Research Plan Summary Objective: Reliably estimate duct leakage fraction for the baseline and efficient case for regional eligible population of SF and manufacture homes. Sample Design and Data Collection – Baseline For 80/20, use the RBSA leakage test results on the 44 applicable homes. For 90/10, perform duct leakage testing on remaining eligible 206 homes in RBSA and study variance in leakage results. – Efficient-Case Select a random sample from prescriptive measure deliveries. – For 80/20: A sample size of 16 SF and 15 manufactured homes – For 90/10: A sample size of approximately 116 SF and 116 manufactured homes Budget (assumes $500/house for duct testing) – For 90/10: $341,000 – For 80/20: $15,500 5 Note: This is a summary. See the Research Plan for more details.Research Plan

6. Research Plan Discussion Will the RBSA sample represent homes that come through the program ? – Current Assumption: Yes – If not, then we may need to do pre-tests, which would likely bias the post leakage measurements. Will 20% precision at 80% confidence on the baseline and efficient-case leakage rates be good enough, or should the plan “require” 90/10 ? – The available baseline data, which satisfies 80/20, shows 28% precision at the 90% confidence level. This means the baseline leakage is anywhere from to 7.1% to 12.5% (at 90% confidence). We might expect the efficient-case leakage to be 5%. That gives us a very wide range of “delta” leakage: 2.1% to 7.5%! – Note that this hasn’t taken into account uncertainty in the efficient-case, yet, which will compound the problem. 6