Ground Source Heat Pumps

Ground-Source Heat Pumps let you tap the natural heat energy in the ground, known as geothermal energy, to provide central heating and hot water for your home. They can help you to save on your energy bills and reduce your carbon emissions. Grants and incentives are also offered by the UK government to encourage their uptake.

A ground-source heat pump installation comprises two main elements: a collector that extracts heat from the ground, and an inside unit. It is typically powered by a level of electricity that is far exceeded by the amount of heat the system generates.

The collector consists of an array of pipework beneath ground level. There are two main types of collector: vertical ground collectors and lake collectors.

Vertical ground collectors make use of a number of boreholes of about 20 cm diameter each, which are drilled deep into the ground and typically extend down about 100 metres. The pipework is buried into these. The number of boreholes needed will vary depending upon the heating requirements of the building to be served, and upon the characteristics of the ground.

Lake collectors instead use horizontally configured loops of pipework that are weighted down to sit on the bottom of a body of water near your home. This may be a natural lake or pond or an artificial one. Only homes situated in large grounds or in remote areas near lakes are likely to bs suitable for lake collectors, but they do have the advantage of high efficiency and a relatively low cost of installation.

The inside unit contains a refrigeration circuit, which amplifies the heat collected, and then distributes it through your domestic copper piping to your home’s central heating and hot water systems.

Planning permission is not usually required where the collector falls within your own grounds, but this should be checked with your local authority. The use of lake collectors in lakes situated outside your private property will require the permission of the landowner, and in these cases, you are advised to consult the local water company too to ensure there are no issues related to the supply of drinking water.

Ground-Source Heat Pumps are less likely to be an attractive choice for homes without a reasonably sized garden, although a vertical (bore hole) collector can address this. See above.

A Ground-Source Heat Pump is unlikely to be a good choice if your home isn’t well insulated. Good levels of roof, floor and wall insulation are desirable as are double glazed windows. Ground-Source Heat Pumps also work better with low temperature central heating systems (e.g. oversized radiators).