Heat Pump Water Heaters

Heat Pump Water Heaters

heat pump water heaterHybrid heat pump water heaters are a new, highly efficient way to heat water. They typically cost half as much to operate as traditional electric resistance water heaters, and can save a homeowner as much as $2,500 over the lifetime of the unit. While they heat water, heat pump water heaters also air condition and dehumidify the space around them.

To understand the concept of heat pumps, imagine a refrigerator working in reverse. While a refrigerator removes heat from a box and expels it into the surrounding air, a heat pump water heater takes the heat from the air and transfers it to water. They are called “hybrids” because in addition to a heat pump they also have traditional electric resistance heating elements for times when demand exceeds what the heat pump can produce.

Financial Example

$ 800 qualified heat pump water heater
+ $ 500 installation
- $ 300 rebate from Efficiency Maine
$ 1,000 net installation cost

$250/yr savings*
4 year payback (25% return on investment)
* Source: energystar.gov accessed 11/18/14

$2,500 lifetime savings
Note: Your actual savings may vary.

Advantages

  • Save up to $2,500 over the life of the unit compared to electric water heating.
  • Reduce need for dehumidification. (Note: because they operate based on hot water demand instead of humidity levels, heat pump water heaters complement, but do not replace, dehumidifiers.)
  • Reduce need for air conditioning.

Disadvantages

  • They are as loud as a dehumidifier so are best installed in an unoccupied room.
  • They can cool an unheated room 3 to 5°F, reducing comfort during the heating season.
  • Condensate must be pumped or drained away from unit.
  • If installed in a conditioned space, the heat that is pumped into the water will have to be replaced by the space heating system. This can reduce savings during the heating season.
  • Air filters must be rinsed regularly.

Take Action

Installation Considerations

  • Because of their noise and cooling effect, heat pump water heaters are better suited to basements than living spaces, especially if there is extra heat available from a boiler.
  • Remember that you’ll need a place to drain the condensate. This can be pumped outside or passively drained to a sink, washing machine drain, or floor drain lower than the heat pump condensate port.
  • For optimum efficiency, install a heat pump water heater where the temperature stays above 45°F and provide at least 750 cubic feet of air space around the unit. This would be a typical 10’ x 10’ room.
  • Be sure to give the unit the recommended clearances from walls to ensure adequate circulation. Be sure the ceiling is high enough to accommodate the unit.
  • Insulate the first few feet on incoming and outgoing pipe to minimize heat loss through distribution.

Here is a video on how to install a heat pump water heater:

Click here for a heat pump water heater brochure/rebate form.

Click here for a heat pump water heater user tips guide.