Project Info
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Project Title
Emerging “Micro” Heat Pumps: Modeling, Testing, and Space-Conditioning Performance Metrics
Project Number ET23SWE0034 Organization SWE (Statewide Electric ETP) End-use HVAC Sector Commercial Project Year(s) 2023 - 2024Project Results
In pursuit of California’s ambitious goal of installing six million heat pumps by 2030, emerging technologies such as micro heat pumps (MHPs) available in multiple form factors can serve as additional options for heating and cooling needs in certain single family and multifamily buildings. MHPs in new form factors are entering the U.S. market that could potentially address critical barriers to the consumer such as high costs to electrify, the skilled labor challenges, limited electrical capacity within existing electric panels, or the split-incentive challenge. MHPs are self-contained, up to 120V, and have variable-speed compressors that can provide space cooling and heating in ambient temperatures down to 5º Fahrenheit (F) or lower for spaces up to 1,000 square feet. The goal of this project was to work collaboratively with key stakeholders to test and model the cooling and heating performance associated with MHP. To do this, the CalNEXT project team networked with manufacturers, trade associations, state agencies, utility representatives, energy efficiency advocates, and regulatory bodies. The project team identified MHP units with various form factors such as saddle type, through-the-wall, portable heat pump and window systems. In tandem with this project, the U.S. Environmental Protection Agency (EPA) finalized its Test Method to determine RAC heating mode performance in July 2024, and defined a new heating performance metric for room heat pumps with various compressor types. The project team formulated its test plan around this ENERGY STAR Final Test method, and performed energy modeling to estimate performance of MHPs in some California climate zones using tested data. The energy modeling approach replicated the analysis performed by DOE and EPA on fractional heating bin hours in the Final Test Method while laboratory testing investigated EPA’s Final Test Method on room heat pumps with different MHP form factors. Although this Final Report presents laboratory testing results on heating and cooling performance of certain MHPs, further investigative testing opportunities exist for these products via CalNEXT or other interested parties.
Project Report Document
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