Ductless Heat Pumps (DHP)in Single Family Homes with Zonal Electric Heat

Proven UES Measure Proposal

Regional Technical ForumNovember 19, 2013

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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

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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

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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.

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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.

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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)

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Screening (continued)

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Screening (continued)

• Proposed duties for DHP Screening Subcommittee:1. Identify workable screen(s) for all zones2. Evaluate their implementation characteristics3. Determine reliability of companion UES(s) for each

screen4. 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

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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

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Last Measure In

 Component Proposed LMI Value

Floor R - 14.4

Wall R - 10.3

Ceiling R - 20.2

Window R - 0.53

Infiltration See note*

• 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.

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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

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Last Measure In (continued)• Difference between LMI and Option 3 savings is likely less

than the difference between current and proposed savings

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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)

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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.”

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Appendix A:

DHP Calibration Summary

Data Source “DHP 95 Study”

Report Name Baylon, David, et.al. "Ductless Heat Pump Impact & Process Evaluation: Field Metering Report." Prepared by Ecotope for NEEA. May 1, 2012.

Summary of Data 95 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 RunsOne run for each of the

95 Houses

inputs

outp

utsSEEM 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°FHZ2: 67.0°FHZ3: 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 RunsOne run for each of the

95 Houses

inputs

outp

utsSEEM 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°FHZ2: 69.2°FHZ3: 66.6°F

(“Good” insulation)

DHP-Zonal Difference for Good Ceiling/Wall/Floor CaseSubtract Electric Resistance Zonal set point from DHP set point

Heating Zone DHP Temp Increase over Zonal

HZ 1 0.8F 0.8F 0.8F 1.2F

HZ 2 2.2F 1.8F 2.5F 3.2F

HZ 3 2.9F 2.4F 1.3F 3.3F

Heating System Electric Resistance Zonal OnlyCeiling / Wall Insulation Good Ceiling or Wall Poor Ceiling or WallFloor Insulation Good Floor Poor Floor Good Floor Poor FloorHZ 1 69.1 67.0 65.3 62.9HZ 2 67.0 64.6 61.8 58.5HZ 3 63.7 60.9 59.5 55.5

Heating System DHPCeiling / Wall Insulation Good Ceiling or Wall Poor Ceiling or WallFloor Insulation Good Floor Poor Floor Good Floor Poor FloorHZ 1 69.9 67.8 66.1 64.1HZ 2 69.2 66.4 64.3 61.7HZ 3 66.6 63.3 60.8 58.8

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 4.8F, DHP 4.3F

Zonal Set-Point from RBSA SEEM “calibration”

66.9F64.8F61.5F

“Calibrated” DHP Daytime Set

Point

67.7F67.0F64.4F

Difference between zonal and

DHP settings

0.8F

2.2F

2.9F

Heating Zone

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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.

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Appendix B: LMI Assumptions

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

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Other Additional Slides

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