Residential Space Heating Opportunities in Cold Climate Regions

This paper’s objective is to present an overview of testing and energy conservation standards regulations in the U.S. for single-phase heat pumps with a cooling capacity of less than 65,000 Btu/h, and how such provisions can be further revised to alleviate possible barriers to heat pump adoption in cold climate regions. While new federal provisions for heat pumps will be implemented starting January 1, 2023, and are expected to yield metrics that are more representative of the average use cycle of a covered product installed in the field, several opportunities continue to exist on improving the performance metrics for heat pumps installed in cold climate regions, including but not limited to a controls verification procedure at a lower ambient temperature point prescribed in a recently finalized ENERGY STAR® specification. Such opportunities include but are not limited to the following: test procedure revisions to address heating mode tests in lower ambient outdoor temperatures that are repeatable and reproducible in laboratory environments, impacts of refrigerant transition on performance ratings, accounting of fan energy consumption for air handlers and crankcase heaters in certain outdoor ambient conditions not addressed in upcoming or existing federal test procedures, performance criteria more relevant to cold climate regions, approaches to demand response in both heating and cooling modes, equipment sizing considerations, controls solutions to minimize the usage of auxiliary heating, and standardized reporting of expanded ratings in technical literature. Addressing these factors will improve HSPF2, the heating seasonal performance metric for heat pumps. The paper will also seek to make a case for regional heat pump energy conservation standards using fractional bin hour weather data for multiple representative cold climate cities. Heat pumps are currently subject to national standards in the U.S. whereas single-phase residential central air conditioners with similar cooling capacities are subject to regional standards.