Our previous post looked at ground source heat pumps as an alternative to gas boilers.
Next up: air source heat pumps.
Air source heat pumps have become popular with domestic setups in the UK, with 87% of people choosing this kind of heat pump.
An air source heat pump absorbs heat from the air outside to heat your home. They do this by blowing air over a series of tubes filled with a liquid refrigerant. This liquid absorbs heat from the air and turns into a gas. The pump uses electricity to compress this gas and raise its temperature - warmth which is then transferred into heat or water, depending on which kind of system you opt for. This heat can be used in your home’s radiators, underfloor heating and hot water systems. Like a ground source heat pump, they use electricity to run, but the heat output is greater than the electricity input, so they are energy efficient. If you put 1 kWh of energy in, you’ll get around 4 kWh out.
There are two main types of air source heat pumps: air to water and air to air.
Air to water pumps can heat your home and your hot water through pipes and radiators. They work particularly well with an underfloor heating system. You can see some case studies on the Energy Saving Trust’s website. Air to water pumps are eligible for the government’s Renewable Heat Incentive (RHI) scheme, which can contribute towards the cost of installing them in the first place.
Air to air pumps heat or cool air in your home, but they won’t heat your water as they only work in air conditioning systems. They’re also not eligible for the government’s RHI scheme, which is something to bear in mind when looking into which system works best for you.
To install an air source heat pump at home, you’ll need some outdoor space with good ventilation around it. They can be placed on the wall or on the floor, and they need less space than ground source heat pumps, which might account for their popularity. Installation costs between £6,000 and £18,000. So marginally cheaper than a ground source pump, but still a fair penny.
I can see why ground source heat pumps aren’t as popular, because you have to have quite a specific set up (including enough space in your garden) and there can be lots of installation work. Personally, I would sway towards an air to water heat pump.
Now we’ve looked at both, which one seems more appealing to you and why?