Setting the record straight on heat pumps

Heat pumps can be fitted into just about any property type, and can be an effective retrofit option for older buildings that are traditionally considered harder to heat.

Each building will have its own specific requirements, but your installer will consider the property itself, as well as its occupants and lifestyles, to find the right heat pump system for your home. They may suggest insulation upgrades, changes to your radiators and pipework, or maybe a particular type of heat pump set-up, to make sure you get an effective, efficient and low carbon heating system.

Don’t believe us? See for yourself how Gwilym and his family installed a ground source heat pump in their 1860s home in North Wales or learn how Joanna upgraded her 1870s home with an air source heat pump.

A properly installed air source or ground source heat pump is more efficient than a gas boiler, which could save you money on your heating bills.

Heat pumps are around 3-4 times more efficient than boilers, because they give out a lot more heat than the electricity they use to run. Although electricity is a lot more expensive than gas or oil at the moment, the higher efficiency means that the running costs often work our similar. And if you’re replacing an old and inefficient system, your bills could go down dramatically.

We estimate that replacing an old (G-rated) gas boiler with an air source heat pump, for example, could save you up to £375 a year on your heating bills (based on an average sized, four-bedroom detached house in Great Britain).

Air-to-water heat pumps are the most common type found in the UK. They work by absorbing heat from the outside air and transferring this heat to water. The system then distributes heat via your wet central heating system, to provide heat to radiators or underfloor heating, as well as hot water to your taps, bath and shower.

Ground source heat pumps can also be used for both heating and hot water. Heat from the ground is absorbed at low temperatures into a fluid inside a loop of pipe buried underground. The fluid then passes through a compressor that raises it to a higher temperature, which can then heat water for the heating and hot water circuits in your home.

Heat pump systems typically come with a warranty of two to three years. Just like a boiler, a heat pump should be serviced annually to ensure it’s working efficiently and to extend the lifetime of the system. You can expect a well maintained and well operated heat pump to operate for 20 years or more.

The biggest component of a heat pump – whether ground source or air source – is usually installed outside your home, so you don’t need to worry about it taking up too much space inside the property.

For ground source heat pumps, if you have enough garden space, the ground loop can be laid horizontally in a trench about a metre or so below ground. Where there isn’t room to do this, you can drill vertical boreholes to extract heat from much further down, typically between 90m and 160m deep.

For air source heat pumps, you’ll need to ensure the external unit has some space around it to get a good flow of air – but this is usually no bigger than an average air conditioning unit. The external unit is connected to an internal unit containing circulation pumps and hot water, which is usually smaller than the average boiler.

You will usually need a hot water cylinder if you have a heat pump, but if you really haven’t got room for one, you could consider a heat battery instead (this does the same job as a hot water cylinder, but it’s much smaller).

Or you could consider a hybrid system with a heat pump and a combi gas boiler – you won’t gain the space from getting rid of the boiler, but you won’t need to find somewhere to put a hot water cylinder either.

Main image credit: 51% Studios Architecture