ORNL building technologies scientists have been instrumental in the research, development and deployment of heat pump water heaters for use in residential applications. Over the past 40 years, ORNL’s support has led to heat pump water heaters demonstrating significant energy performance improvements and carbon emission reductions as compared to conventional electric resistance water heaters. By utilizing the resources of DOE’s Building Technologies Research and Integration Center at ORNL, researchers have collaborated with three main water heater manufacturers, representing more than 90% of the market: A.O. Smith, General Electric, or GE, and Rheem.
These industrial collaborations have addressed efficiency improvements, reduced demand, accelerated life testing, incorporated thermal storage technologies and included lower global warming potential, or GWP, refrigerants. ORNL research supported GE’s introduction in 2008 of the first residential heat pump water heater by a major manufacturer. GE has reported sales of the heat pump water heater increasing to approximately 150,000 units per year by 2022 and sales are anticipated to climb significantly in the future as efficiency standards continue to increase.