Our take: With proper system sizing, placement and installation, heat pumps can cover the entire heating load of almost any building in the contiguous 48 States. They can perform as well or better than dual fuel homes in extreme temperatures. And they can operate sufficiently without electric resistance backup. The best practice for optimal comfort and efficiency is to first improve the building’s envelope through weatherization but even without that heat pumps can perform.
Heat pump technology has been around since the 1970s and has improved steadily since then, especially in terms of ability to function in colder climates. Because of the efficiency and variable capacity of inverter driven compressors, even at 5 degrees Fahrenheit, the highest performance cold climate heat pumps on the market can still deliver roughly 200% efficiency, twice the efficiency of electric resistance heaters. We’ve seen examples of heat pumps performing in northern latitudes that regularly experience subzero temperatures. There are dozens of market-available heat pumps that produce compressor-derived heat as low as -20°F.
Along with our partners, we have successfully implemented heat pump programs and demonstration projects in colder climates for many years, including a Heat Pump Technology Assessment Tool Development for National Grid in Upstate New York, a Cold Climate Air Source Heat Pump (ccASHP) Sizing and Design Visualization Tool for the Northeast Energy Efficiency Partnership and a residential heat pump decarbonization program in Long Island.