Regional Technical Forum November 19, 2013

1. Ductless Heat Pumps (DHP)in Single Family Homes with Zonal Electric HeatProven UES Measure Proposal Regional Technical Forum November 19, 2013

2. Today’s Agenda • Brief Recap from October Meeting • Staff Highlighted Areas • Remaining Discussion Items • Supplemental Fuel Screen • Workbook Documentation • Last-Measure-In • RTF Staff Recommendation • Proposed Decision

3. Recap from October Meeting • Covered a lot of ground • Costs • Calibration • Analysis (including documentation) • Supplemental fuel screen • RTF seemed to show agreement on the general methodology, model calibration, cooling assumptions, and measure costs • A few issues remained outstanding • Documentation of analysis • Supplemental fuel screen • Last-measure-in definition

4. Staff Highlighted Areas • The screen • Staff proposes the formation of a subcommittee to take up supplemental fuel screen. • Staff recommends the RTF move forward with a decision on an unscreened UES. • Workbook documentation • Staff is satisfied with the additions made to workbook documentation since October. • Staff reviewed the logic of the DHP calibration, which is summarized in a flow chart in Appendix A. • Last-measure-in • Staff recommends moving forward with the proposed last-measure-in assumption and updating once “Option 3” has been fleshed out.

5. Screening • Staff has received many thoughtful comments on the DHP screen since October. • To summarize the input that we have received: • A screen is important to many in the region, particularly those in Heating Zone 3. • Want to find a screen that fits with the Guidelines, but programs can still implement. • Subcommittee is the right place to determine an appropriate screen.

6. Screening (continued) • Why should we move forward with the unscreened UES now? • Appears to be general agreement in the unscreened UES • The provisional research plan for DHP sought to update the current unscreened UES value • The proposed, unscreened UES values differ from the current UES values on the books by 11 to 92% (see next slide)

7. Screening (continued)

8. Screening (continued) • Proposed duties for DHP Screening Subcommittee: • Identify workable screen(s) for all zones • Evaluate their implementation characteristics • Determine reliability of companion UES(s) for each screen • Make a recommendation to the full RTF • Subcommittee should have at least (5) voting RTF members with expertise in programs, Zone 3, and DHP savings calibration • RTF staff has collected proposed candidate screens, with pros/cons, which could seed the discussion

9. Documentation • At the October meeting, staff asked to see additional workbook documentation, particularly within the “dhp_perf_models” tab • Since the October meeting, additional documentation has been included in the following areas: • Heat pump performance curves • Fraction of home heated by DHP • DHP heating fraction vs. temperature and heat loss rate • Explanation of how lab vs. field data is used in modeling • Staff is satisfied with the overall documentation

10. Last Measure In • Staff proposal is to use the last-measure-in definition as defined in the proposed workbook • The proposed last-measure-in definition looks at past program achievements, by measure, and forecasts similar achievements over the EUL * Infiltration forecast assumes that 25% of all homes with 8ACH50 or higher are reduced to 7ACH50.

11. Last Measure In (continued) • Pros • Proposed definition is compliant with the Guidelines • RTF and staff agreed that the proposed LMI assumptions were reasonable (at October meeting) • UES would not be held up by the development of “Option 3” • Cons: • Not compliant with the newly-adopted “Option 3” method of calculating interactive savings • UES may be updated once “Option 3” is implemented

12. Last Measure In (continued) • Difference between LMI and Option 3 savings is likely less than the difference between current and proposed savings

13. RTF Staff Recommendation • Approve the unscreened UES as “Proven” category • Set the measure status to “Under Review” • Signals that the implementation of Option 3 is in progress for this measure • All measures affected by Option 3 should be considered “Under Review” • Set the sunset date to March 31, 2014 (given that Option 3 is expected to be ready by January or February)

14. Proposed Decision “I _______________ move that the RTF: • approve the unscreened Ductless Heat Pumps for Zonal Electrically-Heated Single Family Homes measure as a Proven UES; • Set the measure status to ‘Under Review;’ and • Set the sunset date to March 31, 2014.”

15. Appendix A: DHP Calibration Summary

17. For the Pre-Conditions, can we match SEEM heating energy with observed? House Insulation Levels "DHP 95 Study" Observed: Average BillingHistory from pre-period (zonal electric)"DHP 95 Study” table 32: 9347 kWh/yr House Characteristics "DHP 95 Study" Zonal Electric Thermostat Settings SEEM 94 Calibration: Phase I Iterate: Adjust T-stat Settings until there’s a match. Adjusting Zonal Electric T-stat Settings by +2.2°F gives a match, on average. Yes. inputs SEEM Heating Energy, average for all 95 sites (Pre): 9357 kWh/yr SEEM 94 Runs One run for each of the 95 Houses outputs At what temperature settings? HZ1: 69.1°F HZ2: 67.0°F HZ3: 63.7°F (“Good” insulation)

18. For the Post-Conditions, can we match SEEM heating energy with observed? House Insulation Levels "DHP 95 Study" Observed: Average Metered Usage from post-period (DHP)"DHP 95 Study” table 32: 6484 kWh/yr House and DHP Characteristics "DHP 95 Study" Heat Pump Thermostat Settings SEEM 94 Calibration: Phase I Iterate: Adjust T-stat Settings until there’s a match. Adjusting Heat Pump T-stat Settings by -0.4°F gives a match, on average. Yes. inputs SEEM Heating Energy, average for all 95 sites (Post): 6468 kWh/yr SEEM 94 Runs One run for each of the 95 Houses outputs At what temperature settings? “under the hood” inputs DHP1: Results of COP metering for 4 houses with Fujitsu 12RLS, manually fit to a curve. “DHP 95 Study” data 3 DHP Performance Curves (COP vs ODT) Fraction of Heating Energy met by DHP (Function of ODT and UA) DHP2: Results of COP metering for 5 houses with Mitsubishi FD12NA , manually fit to a curve. “DHP 95 Study” data HZ1: 69.9°F HZ2: 69.2°F HZ3: 66.6°F (“Good” insulation) DHP3: Results of COP metering for 3 houses with Mitsubishi A24NA , manually fit to a curve. “DHP 95 Study” data Data from 56 houses, 1+ years, fit to a logistic function using least-squares regression. “DHP 95 Study” data

19. DHP-Zonal Difference for Good Ceiling/Wall/Floor Case • Subtract Electric Resistance Zonal set point from DHP set point

20. Regional “Calibrated” SEEM T-stat Settings for DHP • Add difference found between zonal and DHP from DHP “calibration” to regional SEEM “calibration” t-stat settings for zonal houses: • 9hr night time setback: ER 4.8F, DHP 4.3F Q: Why do it this way? A: The DHP 95 study does not represent the Region as well as RBSA; homes in the DHP 95 study show higher average heating energy use than the RBSA homes. This method “normalizes” the heating energy use to RBSA levels.

21. Appendix B: LMI Assumptions

22. Floor and Ceiling Forecast, 15 years

23. Wall and Window Forecast, 15 years

24. Assumptions and Comments • Blue bars show the current distribution by component • Zonal electric only • Pre 1980 vintage only • About half the upgrades observed in this group in RBSA (30 years of accomplishments) are added • Red bars are the increase in each component • Aggregate UA implied by these changes used to project savings

25. Other Additional Slides