Heat Pump Water Heaters: Savings Potential in Minnesota
Ben Schoenbauer, Dave Bohac, P.E., Martha Hewett — Dec 2012
Heat pump water heaters remove heat from the surrounding air and transfer it to water. Moving heat requires less energy than generating it directly, so they can be an efficient direct replacement for traditional electric storage water heaters.1 Heat pump water heaters are becoming more common in southern states, but their savings potential in Minnesota’s heating-dominated climate is undefined. And recent laboratory studies suggest that their performance rating does not accurately reflect installed energy savings.
This white paper will attempt to characterize heat pump water heaters’ capacity to reduce space heating energy use in Minnesota single-family homes with electric water heaters. Engineering calculations will determine potential impacts of several different unit installation configurations. It will also review existing field studies on residential water usage and heat pump water heater performance, then apply the findings and concepts to Minnesota’s housing stock, water use patterns, and climate. CEE will also create two online calculators for rebate programs and homeowners.
This project supported in part by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program. And with co-funding by CEE in support of its nonprofit mission to advance research, knowledge dissemination, and program design in the field of energy efficiency.
Photo courtesy of DOE/NREL.