Residential Multi-Function Heat Pump Laboratory Testing

Heat pump space conditioning and water heating can greatly reduce energy consumption compared to existing electric resistance or natural gas combustion options. Requirements for electrical service upgrades add cost and installation delays for customers considering retrofitting heat pumps for space conditioning and or hot water heating. 30% to more than 50% of all homes are expected to require electrical service panel upgrades to fully electrify. Residential Multi-Function Heat Pumps (MFHP) use one efficient compressor and outdoor heat exchanger coil to provide space cooling, space heating, and domestic hot water heating.  These systems offer many energy efficiency benefits.  Air-to-air versions of these MFHP systems have the potential to eliminate the need for electric resistance backup heaters reducing the maximum power requirements so that full capacity systems can fit on existing electrical panels in many retrofits.  The only commercially available air-to-air MFHP in California is the Villara AquaThermAire which is single speed equipment using R-410A refrigerant. This equipment design has been approved for safety and capacity ratings through 3rd party (Intertek) ratings testing. The UC Davis Western Cooling Efficiency Center (WCEC) completed a PGE funded emerging technologies project field testing this prototype system along with Frontier Energy. Preliminary results show good energy efficiency performance for the typical space conditioning and water heating modes as well as the capability to use waste heat from space cooling to heat hot water during the summer. This project will test the efficiency and capacity performance of the Villara AquaThermAire air-to-air MFHP across a range of outdoor air conditions to match California climate zones for space heating, space cooling, water heating, and for simultaneous space cooling with heat recovery water heating. These lab test results will then be used to develop equipment performance curves for use with EnergyPlus and CBEC-Res to estimate energy savings in residential buildings. This project will enable energy savings estimates for custom efficiency programs and for development of a measure package  for deemed efficiency programs. Future laboratory tests of one or more competing air-to-air MFHP will evaluate the range of MFHP equipment performance, and field demonstrations will verify installation cost savings, energy savings, and customer satisfaction including sites in DAC and HTR customer buildings.