I have to replace my old electric water heater and wonder if I should get a heat pump water heater?
Heat pump water heaters hold a lot of promise as a technology to help reduce energy use in the Northwest.
To test the units, Clark Public Utilities is participating in a demonstration project with the Bonneville Power Administration and the Electric Power Research Institute.
BPA estimates heat pump water heaters have an energy-savings potential of 50 percent of more. As part of the demonstration, heat pump water heaters are being installed at 40 sites throughout the region.
“These are relatively new here and we’ve only installed them for the test,” said Curt Cheever of Roto-Rooter Plumbing and Drain Service in Portland. “All have been retrofits and located in garages.”
How they work
Heat pump water heaters operate like the heat pumps that heat and cool homes.
A fan draws in air through a filter. Heat in the air is absorbed by a refrigerant inside an evaporator coil. Cool, dehumidified air is exhausted. The heated refrigerant coil transfers the heat to the cool water and the resulting hot water is stored in an insulated tank, like standard electric water heaters.
Traditional electric heating elements act as a backup in case you need to boost water temperature or have a need for more hot water than usual.
Location matters
Heat pump water heaters should be located where temperatures get no lower than 40 degrees to be the most efficient. They exhaust cold air, so you wouldn’t want to locate them in a heated space, such as a basement. They also need plenty of air around them — about 1,000 cubic feet — which rules out closet installations.
Finally, heat pump water heaters’ compressor fans operate three to four hours a day, so you need to consider the resulting noise.
“Their noise is comparable to a refrigerator,” Cheever said. “They’re getting better, but we have had to do some noise cushioning on units that were located on a wall next to a living space.”
Costs and incentives
Presently, heat pump water heaters cost around $1,500, according to Cheever. A superefficient traditional electric water heater runs around $900.
However, Energy Star-qualified heat pump water heaters with an energy factor of 2.0 qualify for a $250 rebate through Washington’s Cash for Appliances program.
In addition, if you install a qualifying unit by Dec. 31, you may qualify for a 30 percent tax credit, up to $1,500. Be sure to check which models qualify before making your purchase.
“We will learn more about the effectiveness of heat pump water heaters in the Northwest,” said DuWayne Dunham, Clark Public Utilities energy counselor. “We know the technology is very efficient, so we’re hoping these water heaters can do what the air-to-air heat pump did for heating and cooling in this area.”
The Energy Adviser is written by members of the energy counselor team of Clark Public Utilities, who provide conservation and energy use information to utility customers. Send questions to energyadviser@clarkpud.com or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA. 98668. A panel of local energy efficiency and energy product specialists will review your questions. Previous topics are available at http://www.clarkpublicutilities.com.
