Available Modules

Heat Pump Water Heaters (HPWH)

The Heat Pump Water Heater (HPWH) is a highly efficient water heating system that utilizes heat pump technology to heat potable water rather than air for space conditioning. It is a system in that most heat pump configurations also require a back-up heat source such as an electric or gas storage water heater. At the very least, a tank is needed to store the heated water. Very high efficiency is obtained because the HPWH extracts, rather than generates, heat from a medium such as air and transfers that heat to the water. Although the HPWH offers the added benefit of air cooling, its primary function is water heating.

Despite its energy efficiency, the commercial market for Heat Pump Water Heaters is very small–perhaps not as large as 1,000 units/year nationally–compared to approximately 155 thousand water heaters shipped annually to the commercial market.

HPWHs are best suited to applications that meet heavy hot water requirements over long periods of time with electric resistance water heaters and that require spot cooling or dehumidification. HPWHs have been used in restaurants and laundromats regardless of climate. Indoor pools, athletic facilities, hotels and apartment buildings have also installed HPWHs.

In studies done by DOE, it was noted that heat pumps, in general, are not very efficient at low temperatures– less than 50°F. Additionally, HPWHs require a back-up heat source, usually expensive electric resistance heating. DOE determined that HPWHs are only efficient in select regions of the U.S. and only when compared to electric resistance water heating.

Further issues with HPWHs concern space limitations and the lack of a manufacturing, sales and service infrastructure. For maximum operating efficiency, a HPWH must be surrounded by at least 1,000 cubic feet of air space and installed in locations that remain between 40° and 90°F year round.

Heat Pump Water Heater