To understand the concept of heat pumps, imagine a refrigerator
working in reverse. While a refrigerator removes heat from an
enclosed box and expels that heat to the surrounding air, a heat
pump takes the heat from surrounding air and transfers it to water
in a swimming pool.
Heat pump technology makes efficient use of the heat in the surrounding air,even at temperatures as low as -7°C. Infact the Enviroheat system is so efficient that it can convert 1kW of electricity into over 4kW of heat.