Insider Tips with Cooperative Energy Expert Tim Johnson features advice on energy efficiency, new technology and electric appliances. Have a question for Tim? Leave a comment on this post with an email address and he’ll reply.
How a heat pump water heater works:
There are two types of heat pump water heater. The add-on unit is installed on an existing electric resistance water heater. The other, an integrated or drop-in unit, replaces an existing electric water heater. The heat pumps work in essentially the same way, though the add-on units aren’t efficient enough to qualify for an ENERGY STAR rating.
The heat pump draws heat from the surrounding air and uses it to heat water in a tank, like a reverse refrigeration system. Heat pump water heaters have at least one backup electric resistance element in the tank, for use when the ambient air is too cold for heat pump operation or larger amounts of hot water are needed. The cool exhaust air is released into the area where the heat pump water heater sits, cooling and dehumidifying the surrounding air. The new-generation models on the market cannot duct the exhaust air outside. However, manufacturers plan to remedy the external ducting issue.
The heat pump water heater uses electricity to move heat from one place to another,rather than to generate heat. As a result, the unit uses roughly half the electricity of a conventional electric water heater.
Water heating is the second largest energy end use in homes, accounting for between Continue reading