Residential heat pump water heaters have been readily commercially available in the United States since the early 1970s. Due in no small way to the oil embargo of 1972, a large number of manufacturers designed and began producing residential heat pump water heaters in the 1970s and early 1980s. At one point there were more than 15 brands of residential heat pump water heaters on the market, produced by many prominent brand-name companies, as well as smaller new companies.

Unfortunately, the early operating experience with residential heat pump water heaters was not good. Many of the products on the market had been introduced without adequate long-term testing and exhibited unacceptable failure rates and maintenance requirements. As a result, most brands of residential heat pump water heaters are no longer on the market.

This paper describes some of the historical problems encountered with residential heat pump water heaters and operating experiences with newer-model residential heat pump water heaters from one of the surviving brands, installed in the author’s residence. Operational behavior, sound issues, moisture removal benefits, maintenance requirements, and energy consumption are all discussed.

Units: Dual