Heat pump water heaters use energy from the outdoor air or ground to heat water, which is stored in an insulated hot water tank. The actual efficiency that you get from a heat pump water heater depends on the make of the system, the quality of the installation, the average temperatures where you live and the location of the compressor unit.
There are two different types of heat pump water heaters:-
- Split systems
- All-in-one units
Split systems have the compressor unit outside and the hot water tank generally inside although the tank can also be located outside the house separate from the compressor. In some cases you can use your existing hot water tank.
All-in-one units have the compressor and tank together and the whole system usually sits outside.