Ground Source Heat Pump
Heat your home with energy absorbed from the ground
Ground source heat pumps use pipes buried in the garden to extract heat from the ground. This is usually used to heat radiators or underfloor heating systems and hot water.
Beneath the surface, the ground stays at a fairly constant temperature, so a ground source heat pump can be used throughout the year - even in the middle of winter.
How does a ground source heat pump work?
A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe - called a ground loop - which is buried in the garden. Heat from the ground is absorbed into this fluid and is pumped through a heat exchanger in the heat pump. Low grade heat passes through the heat pump compressor and is concentrated into a higher temperature useful heat capable of heating water for the heating and hot water circuits of the house. Ground loop fluid, now cooler, passes back into the ground where it absorbs further energy from the ground in a continuous process while heating is required.
The length of the ground loop depends on the size of your home and the amount of heat you need - longer loops can draw more heat from the ground, but need more space to be buried in.
Normally the loop is laid flat, or coiled in trenches about two metres deep, but if there is not enough space in your garden you can install a vertical loop down into the ground to a depth of up to 100 metres for a typical domestic home.
Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air, or water is constantly being renewed naturally.
Unlike gas or oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. This means that during the winter they may need to be left on 24/7 to heat your home efficiently. It also means that radiators should never feel as hot to the touch as they would do when using a gas or oil boiler.
The benefits of ground source heat pumps
- Can reduce your carbon footprint: heat pumps can lower your home’s carbon emissions, depending on which fuel you are replacing
- No fuel deliveries required
- Can provide space heating and hot water
- Can lower fuel bills, especially if you are currently using conventional electric heating
- It's often classed as a ‘fit and forget’ technology because it needs little maintenance
Is a ground source heat pump suitable for my home?
To tell if a ground source heat pump is right for you, there are a few key questions to consider:
- Is your garden suitable for a ground loop? It doesn't have to be particularly large, but the ground needs to be suitable for digging a trench or a borehole and accessible to digging machinery
- Is your home well insulated? Since ground source heat pumps produce a lower temperature heat than traditional boilers, it's essential that your home is insulated and draught proofed well for the heating system to be effective. It could also make the system cheaper and smaller
- What fuel will you be replacing? If you're replacing an electric, or coal heating system, a ground source heating system will save you more on your heating bills. Heat pumps are not recommended for homes on the gas network.
- What type of heating system will you use? Underfloor heating systems, larger radiators or low temperature fan convectors (warm air heating) can perform better than standard radiator-based systems because of the lower water temperatures required.
- Is the system intended for a new development? Combining the installation with other building work can reduce the cost of installing the system.