Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly through the combustion of fossil fuels or electric resistance heating. Like a refrigerator working in reverse, heat pump water heaters take the heat from surrounding air and transfer it to water in an enclosed tank. During periods of high hot water demand, heat pump water heaters can automatically switch to standard electric resistance heat.Ā
Upgrading from a gas to a heat pump water heater is one of the most effective ways to reduce energy use and emissions in a home, given that water heating accounts for about 18% of the average homeās energy use and is typically the second largest energy expense in any home.Ā

Figure 4: Components of a heat pump water heater, sourced from the Building America Solution Center.