Taking heat from the air and heating your house
Air Source Heat Pumps (ASHP) heat your house from the air outside. It may sound counter intuitive, but just as a fridge extracts heat from the inside, so ASHPs extract the heat from the outside, working to temperatures as low as -15°C (outside).
Depending on system configuration an ASHP can offer a full central heating solution and provide domestic hot water. Most heat pumps can also operate in a cooling mode where the cold refrigerant is moved through the indoor coils to cool the room air.
This renewable heating technology tends to best suit relatively well insulated homes.