Air source heat pumps use the outside air temperature as an energy source converting any temperature differentiation into useable heat to run heating or water heating systems.

An air source heat pump is usually installed on the outside of a building and can easily be retrofitted. GSHP systems typically operate at temperatures of around 55°C , hence their suitability for under floor and water heating , low temperature radiators or fan confection heaters.

They best suit buildings with adequate insulation and do not work with existing high temperature radiators. Systems may also be eligible for subsidy payments under the Renewable Heat Incentive.