Air source heat pumps (ASHPs) absorb heat from the outside air to heat your home and hot water. They can still extract heat when air temperatures are as low as -15°C.
If you have large garden space outside, you could consider a ground source heat pump. ASHPs need electricity to run, but because they are extracting renewable heat from the environment, the heat output is greater than the electricity input.
How do air source heat pumps work?
Heat from the air is absorbed at low temperature into a fluid. This fluid passes through a compressor, increasing the temperature, and transfers that higher temperature heat to the heating and hot water circuits of the house.
There are two main types of ASHP: air-to-water and air-to-air. Choosing an air-to-water or an air-to-air system will determine the type of heat distribution system you need.
Air-to-water heat pumps absorb heat from the outside air, and transfer the heat to water.
An air-to-water system distributes heat via your wet central heating system. Heat pumps work much more efficiently at a lower temperature than a standard boiler system would. This makes them more suitable for underfloor heating systems or larger radiators, which give out heat at lower temperatures over longer periods of time.
Air-to-water heat pumps are the most common model in the UK.
Air-to-air heat pumps require a warm air circulation system to move the warm air around your home. They will not provide you with hot water as well. Air-to-air heat pumps are not eligible for the UK Government’s Renewable Heat Incentive (RHI) scheme.