Heat Pump

A device that extracts heat from the air (air source) or ground (ground source) and upgrades it to a useful temperature for space heating and hot water. Heat pumps are highly efficient - for every unit of electricity consumed, they deliver 2–4 units of heat (expressed as COP, Coefficient of Performance). They require a well-insulated building and work best with low-temperature heat emitters such as underfloor heating or oversized radiators.