Types of heat pumps

Air source heat pump

An air source heat pump is the most common type of heat pump and is the type you can get through the switch together scheme. It works by drawing warmth from the air outside to heat a refrigerant liquid. This then passes the resulting gas through a compressor to increase the temperature and send it to heat your hot water in your pipes and hot water cylinder. The water in your pipes heats your home through your radiators.

On average, a high-efficiency cold climate air-source heat pump will cost around £15,000. However, with the Boiler Upgrade Scheme (BUS), you may be eligible for the £7,500 government grant, and through initiatives like Switch Together, you could save even more through the power of group buying. Additionally, VAT on energy-saving materials has been reduced from 5% to 0% from April 2022 to April 2027.

An air source heat pump can still work in lower temperatures (up to -20C), so you won’t need to worry about heating your home in those colder winter months. They are also much more energy efficient than your regular gas boiler. Air source heat pumps work at 300% efficiency, whereas an average gas boiler works at 90%.

Ground source

A ground source heat pump works in a similar way to an air source heat pump, but draws warmth from below ground. They can be more efficient than air source heat pumps, but are a more invasive product as you’d need to dig up land to install the heat pump.

To give you an idea of the operation required, an average three-bedroom house would need around 400m2 of ground area to fit a horizontal system. You can opt for a vertical system, but it requires boreholes to be drilled between 80 and 160 metres into the earth, making the installation even more complex and expensive.

Good to know: Ground source systems are not offered by Switch Together due to the space requirements and long installation process.

Water source

Next, we have the water source heat pump, which uses the same science but absorbs warmth from bodies of water. They are typically even more efficient, as heat transfers better through water than air. Efficiencies can reach between 400% and 500%. Water temperatures are steady throughout the year, so you can maintain consistency in your heating.

Good to know: Switch Together does not offer water source as they require you to have access to a nearby body of water.