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

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 2

Recap from October MeetingOctober 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 3

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. 4

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. 5

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)proposed, unscreened UES valuescurrent UES values 6

Screening (continued) 7

Proposed duties for DHP Screening Subcommittee: 1.Identify workable screen(s) for all zones 2.Evaluate their implementation characteristics 3.Determine reliability of companion UES(s) for each screen 4.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 8

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 9

Last Measure In ComponentProposed LMI Value FloorR WallR CeilingR WindowR InfiltrationSee note* 10 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.

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 11

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

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) 13

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.” 14

Appendix A: 15 DHP Calibration Summary

Data Source“DHP 95 Study” Report NameBaylon, David, et.al. "Ductless Heat Pump Impact & Process Evaluation: Field Metering Report." Prepared by Ecotope for NEEA. May 1, Summary of Data95 homes, screened for wood heat use, received a DHP -Houses received a detailed energy audit. -“Quad metering” consisted of energy metering of the DHP, the baseboard heating, the DHW, and the whole house. -IDT and ODT were measured, as was cooling/heating state. -Bills were analyzed pre- and post-DHP installation. A sub-sample of 35 homes received a detailed metering package designed to measure DHP heat output (real-time COP).

Observed: Average Billing History from pre-period (zonal electric)"DHP 95 Study” table 32: 9347 kWh/yr Zonal Electric Thermostat Settings SEEM 94 Calibration: Phase I House Insulation Levels "DHP 95 Study" House Characteristics "DHP 95 Study" SEEM 94 Runs One run for each of the 95 Houses inputs outputs SEEM Heating Energy, average for all 95 sites (Pre): 9357 kWh/yr For the Pre- Conditions, can we match SEEM heating energy with observed? 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. At what temperature settings? HZ1: 69.1°F HZ2: 67.0°F HZ3: 63.7°F (“Good” insulation)

Observed: Average Metered Usage from post-period (DHP)"DHP 95 Study” table 32: 6484 kWh/yr Heat Pump Thermostat Settings SEEM 94 Calibration: Phase I House Insulation Levels "DHP 95 Study" House and DHP Characteristics "DHP 95 Study" SEEM 94 Runs One run for each of the 95 Houses inputs outputs SEEM Heating Energy, average for all 95 sites (Post): 6468 kWh/yr For the Post- Conditions, can we match SEEM heating energy with observed? Yes. 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. “under the hood” inputs 3 DHP Performance Curves (COP vs ODT) Fraction of Heating Energy met by DHP (Function of ODT and UA) DHP1: Results of COP metering for 4 houses with Fujitsu 12RLS, manually fit to a curve. “DHP 95 Study” data DHP2: Results of COP metering for 5 houses with Mitsubishi FD12NA, manually fit to a curve. “DHP 95 Study” data 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 At what temperature settings? HZ1: 69.9°F HZ2: 69.2°F HZ3: 66.6°F (“Good” insulation)

DHP-Zonal Difference for Good Ceiling/Wall/Floor Case Subtract Electric Resistance Zonal set point from DHP set point Heating ZoneDHP Temp Increase over Zonal HZ  F 1.2  F HZ  F1.8  F2.5  F3.2  F HZ  F2.4  F1.3  F3.3  F Heating SystemElectric Resistance Zonal Only Ceiling / Wall InsulationGood Ceiling or WallPoor Ceiling or Wall Floor InsulationGood FloorPoor FloorGood FloorPoor Floor HZ HZ HZ Heating SystemDHP Ceiling / Wall InsulationGood Ceiling or WallPoor Ceiling or Wall Floor InsulationGood FloorPoor FloorGood FloorPoor Floor HZ HZ HZ

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 Zonal Set- Point from RBSA SEEM “calibration” 66.9  F 64.8  F 61.5  F “Calibrated” DHP Daytime Set Point 67.7  F 67.0  F 64.4  F Difference between zonal and DHP settings 0.8  F 2.2  F 2.9  F Heating Zone 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.

Appendix B: LMI Assumptions 21

Floor and Ceiling Forecast, 15 years

Wall and Window Forecast, 15 years

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

Other Additional Slides 25

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