Guides
Air-to-air or air-to-water: which heat pump suits your home?
Compare air conditioning style heat pumps with air-to-water systems for cost, comfort, hot water and grants.
The short answer
Air-to-air (air conditioning) heats and cools room by room and is cheaper and quicker to fit. Air-to-water replaces your boiler, runs radiators and also heats your hot water. Many homes end up with a mix: air-to-water for the whole house, or air-to-air in the rooms you use most plus a separate hot water solution.
Air-to-air suits you if
- you want cooling in summer
- you live in a flat or a smaller home
- you want to cut the use of an old boiler or electric heaters quickly
- you do not want to change radiators
Air-to-water suits you if
- you want one system for heating and hot water
- you have room for a cylinder
- you want the largest grant (£7,500, or £9,000 from oil)
Hot water is the key question
Air-to-air systems do not heat water. If you have a combi boiler and replace it with air-to-air, you still need a way to heat water, such as keeping the boiler for hot water only, a heat pump cylinder or an immersion cylinder with solar.