Air to Air vs Air to Water Heat Pumps: Which Do You Need?

Both types take heat from the outside air. The difference is what they do with it. An air-to-water heat pump heats water, which then runs through radiators or underfloor heating and heats your hot water cylinder. An air-to-air heat pump heats air directly and blows it into rooms through indoor units.

Air-to-water is a whole-house replacement for a boiler. It heats every room through your existing pipework and radiators, often with some radiators upgraded, and it gives you hot water for taps and showers. It's the type most UK homeowners mean when they talk about a heat pump.

Air-to-air works like a reversible air conditioner. Wall-mounted indoor units warm rooms in winter and cool them in summer. It's quick to install and very efficient for heating individual rooms, but it doesn't provide hot water, so you'd still need another way to heat water.

Grants are a big difference. Air-to-water heat pumps can qualify for the £7,500 Boiler Upgrade Scheme grant when installed by an MCS certified installer. Air-to-air heat pumps are not eligible for the scheme.

So which do you need? If you want to replace your boiler and heat the whole house and your hot water, an air-to-water heat pump is usually the answer. If you want efficient heating and cooling in a few rooms, such as a home office, extension or flat, air-to-air can be a good fit.

Casa Renewables installs both, so we'll recommend what suits your home rather than what we happen to sell. Book a free survey and we'll talk you through the options.