Heat Pump

Heat pump water heaters, also called hybrid electric water heaters, are an efficient all-electric option. They pull heat from the surrounding air and transfer it to stored water. They can be four times more efficient than traditional electric resistance water heaters, because it takes substantially less energy to transfer than to generate heat. However, it takes longer to heat water with a heat pump, so these units have electric resistance heating elements for when hot water is in peak demand. 

Heat pump water heaters will also help to dehumidify the space they are in. When they pull heat from the surrounding air, they leave cool, dry air in its place. Locating a heat pump water heater in a damp area, such as a basement, can improve the quality of air in your home. 

Heat pump water heaters can cost less to operate than electric resistance, propane, or even gas water heaters (depending on electricity and gas prices). However, they may cost more to purchase, and switching from propane or gas may require wiring upgrades.

A heat pump water heater must be installed in a room of sufficient size (450-1000 cubic feet, depending on the unit), and they are generally taller than traditional water heaters. They also require a drain for the condensed water that results from removing heat from the air. 

Heat pump water heaters produce a low humming sound. Although this humming typically does not exceed 40 decibels (dB), it can reach up to 60 dB on colder days. A boiler often has the same noise level as a heat pump, with a range of 40 to 60 dB. For perspective, 40 decibels is comparable to a refrigerator; 60 dB is akin to the noise created by an electric toothbrush.