Deeming Savings for Ductless Heat Pumps in Manufactured Homes Regional Technical Forum January 4 th, 2011

Background: RTF History for DHP’s Single Family Homes = 3,500 kWh/year – With Zonal Electric Heat – November 2007November 2007 Justification: – The main living area consumes the majority of the heating energy, so installing a DHP there could offset a significant amount of heating energy use in these houses. – Occupants still have the same zonal control they’re used to. – 3,500 kWh/year seemed reasonable given the heating loads; it was also the lowest value that still resulted in a cost-effective measure. – With Forced Air Furnaces – September 2008September 2008 Justification: – FAF heated houses use more heating energy than zonal electric heated houses, so the savings should be at least equal to zonal, if not more. – Notes: Savings are “provisionally” deemed. Whether these savings would have been approved under the new proposed guidelines is questionable. Both decisions were made with the following pressure from RTF stakeholders: “We need a deemed value from the RTF in order to run the program.” Savings for manufactured homes were proposed at the September 2008 meeting, but not approved. September 2010, the RTF announced it had mistakenly published deemed savings for DHP’s in manufactured homes. September 2010 – BPA has requested the RTF look into properly deeming the measure. 2

Issues with the FAF “Equal or Better” Savings Theory How will the FAF thermostat interact with the Ductless Heat Pump thermostat? – Depends on occupant behavior (???) How should the occupant control the temperature in other parts of the house? – Using the FAF will probably cause decreased savings from DHP Should the occupant try to use the duct system to deliver “DHP heat” to the rest of the house? (NO!!!) – Turning off the FAF could cause comfort issues 3

Baseline Energy Consumption (SEEM runs) Notes: – Single Family SEEM runs have been calibrated to billing analyses; manufactured home runs have not. – These SEEM runs assume fully weatherized houses. 4

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Proposed Measures 6 NOTE: These values are for illustrative purposes only. The purpose of this presentation is to show that these deemed measures should not be created (because we don’t have manufactured home-specific data).

7 Primary Issue (needed for provisional) [Next] Primary Issue (needed for deemed)

Recommendation: Do Not Deem at this Time What would be needed to deem: – Data Baseline Energy Consumption Efficient-Case Energy Consumption – Specific to Manufactured Homes – Calibration of the engineering model to the data – Estimated Level of Effort to Deem = High Alternatives to Deeming – Standardized Protocol Possible Alternative – Would need same data as for deeming – Custom Protocol Poor Alternative – Too expensive. Small savings. – Run a program and perform an impact evaluation to determine savings Good Alternative 8