Even at sub-zero temperatures, the outside air contains heat. An air source heat pump enables users to extract this heat for use in homes or buildings.
Air source heat pumps work in a similar way to domestic refrigerators, by using a vapour compression cycle to provide heating or cooling. This vapour compression cycle means that low level heat from outside is upgraded to higher level heat which can be released into the building.
Air source heat pumps can reduce heating bills and can also be used as cooling units in the summer. They are easy to install, largely unobtrusive and emit less CO2 than traditional fossil fuel-based heating systems. However, they do require electricity to run and their performance declines as the temperature falls. It is unlikely that they will be able to fulfil the peak demand for heating and hot water and will, therefore, require a back-up system.