Busting Myths About Heat Pump Water Heaters

Homeowners typically spend up to 20 percent of household energy use on water heating, making it the second-highest driver of energy expenses after heating and cooling. Using up to 70% less energy than traditional gas systems, ENERGY STAR certified heat pump water heaters (HPWHs) are the most energy-efficient water heating technology available to homeowners looking to cut energy costs and boost energy savings.  

As the name suggests, the efficiency of HPWHs is made possible by heat pump technology, which leverages warm indoor air to heat water for your household. This use of warm indoor air often leaves homeowners concerned that HPWHs will make their homes colder, particularly in the winter, when household heating needs are high and, in turn, increase overall energy costs. 

ENERGY STAR experts dive into the research to help bust these myths: 

Summary: 

Myth 1: Heat pump water heaters freeze your basement.

Fact: HPWHs do not cause extreme temperature drops in your home. On average, HPWHs reduce room temperature by 2.3° F and go largely unnoticed by homeowners, even in the winter.

Myth 2: HPWHs increase the cost of heating your home in the winter.

Fact: Energy and cost savings of using a HPWH are found to offset any additional whole-home heating costs during winter months.

Myth 3: HPWHs won’t work in cold climates.

Fact: Advances in heat pump technology enable HPWHs to be cost-effective and energy-efficient even in cold climates.

Myth 1: Heat Pump Water Heaters Freeze Your Basement.

Fact Check: HPWHs are found to drive minimal temperature reductions (average of 2.3 ° F) and go largely unnoticed by homeowners who report indifference to temperature changes in both winter and summer seasons. 
 

A 2022 Slipstream study evaluated temperature shifts, customer satisfaction, and cost-effectiveness for 81 households with basement HPWH systems. On average, HPWHs drove minimal temperature reductions of 2.3° F. Temperature drops were also found to return to normal within 4 hours of system operation. When assessing customer satisfaction, the majority of participating homeowners expressed indifference to temperature shifts during both the winter and summer seasons, suggesting that changes to basement room temperatures largely go unnoticed, even in the winter (See Figure 1).

Myth 2: HPWHs Increase the Cost of Heating Your Home in the Winter. 

Fact Check: HPWHs are shown to have no impact on whole-home energy consumption in the winter and were found to drive significant energy savings in the summer.  

A joint study conducted by the Canadian Centre for Housing Technology (CCT) and The National Research Council compared the whole-home energy use for homes with and without a HPWH. Monitored under the same cold-weather conditions, researchers found that increases in heating loads were offset by HPWH energy savings and, as a result, did not impact whole-home heating costs. HPWHs were also observed to consume 3000-35000 Watts(W) less than a standard resistance water heater, resulting in household energy savings of 60% in the winter and summer months.

Myth 3: HPWHs Won’t Work in Cold Climates. 

Fact Check: Technological advancements in heat pump technology enable HPWHs to be cost-effective and operate efficiently in very cold temperatures and are the preferred heating system of homeowners living in cold-weather regions such as Maine.

Modern HPWHs can operate efficiently in temperatures ranging from 35°F to 120°F. When temperatures drop below 35°F, the unit automatically switches from heat pump mode to electric resistance heating. Manufacturers recommend setting HPWHs to hybrid mode by default to optimize performance. Proper control settings are crucial for efficiency. These units can be installed in most locations suitable for standard water heaters, even in cold climate basements. HPWHs are 3-5 times more efficient than traditional water heaters, offering significant energy savings, especially in spaces consistently above 37°F.

Where can I learn more about ENERGY STAR certified heat pump water heaters? 

You can learn more about the benefits of installing an ENERGY STAR certified heat pump water heater and why it’s a key element of an ENERGY STAR Home Upgrade, on our website. 

Also, make sure to look for available savings and incentives for heat pump water heaters on the ENERGY STAR home savings tool. This tool is your one-stop-shop to find all of the savings that are available in your area for this upgrade, including utility rebates and federal income tax credits of up to $2,000 for heat pump water heaters as part of the Inflation Reduction Act.