2 Types of Heat Pump Water Heaters

You should investigate different types of heat pump water heaters if you want to cut down on your energy use and save money in the process. Heat pumps are special heating devices that transfer heat from outside your home to the inside. By transferring heat instead of burning fuel to create it, heat pumps use less fuel than their traditional counterparts. While many heat pumps are used as a central heating system, you can also use a heat pump to heat water in your home. What follows should explain to you the differences between the two main types of heat pump water heaters.

Air Source

Air source heat pumps are one of the two main varieties of heat pumps that can be used as a water heater. They function by removing heat from the air surrounding your home and transferring it inside. They run a loop of pipes that go between the inside and outside of your home and contain a refrigerant with special properties. Then they use a pump, powered by either electricity or natural gas, to circulate the liquid. As the liquid is pumped outside, it expands and evaporates into a gas. It absorbs whatever heat is present. As it is pumped back inside, it is forced to compress. Compression causes it to condense into a liquid and give off the heat it absorbed.

Once the heat is inside your home, it is transferred by close contact to your water heater unit. You can refit a standard water heater to work with a heat pump instead of a traditional furnace.

Air source heat pumps are energy-efficient. By relying on heat that already exists, they can lower your energy consumption and save you money. Unfortunately, they do have one drawback. The colder the temperatures are outside, the less energy-efficient these heat pump water heaters become. Because of this drawback, you shouldn't use air source heat pumps in areas where temperatures regularly drop below freezing.


Geothermal heat pumps can be used to heat water in much the same way that air source heat pumps can. However, instead of using heat from the air outside, they use the soil deep underground that maintains a moderate temperature year-round.

In a water heater run by a geothermal heat pump, a loop of pipes travels between a location deep below the soil and the water heater. The liquid in the pipe, usually water or antifreeze, travels between the two locations. As it travels it picks up heat and deposits it in the water inside your home.

Geothermal heat pump water heaters are also great at conserving energy and saving money. Unfortunately, they are quite expensive to set up. Installing a geothermal heat pump water heater involves digging deep into the ground and installing pipes there. This installation requires a great deal of specialized labor that does not come cheaply.