How does a Ground Source Heat Pump work?

Essentially, a Ground Source Heat Pump allows you to heat water for your home with pipes buried in the garden which extract heat which is already being stored underground. This is usually used to warm water for radiators or underfloor heating systems. It can also be used to pre-heat water before it goes into a more conventional boiler. Beneath the surface, the ground stays at a constant temperature (9-14 degrees), so a Ground Source Heat Pump can be used throughout the year – even in the middle of winter.

heat-pumpsA Ground Source Heat Pump circulates a mixture of water and a glycol mixture (to prevent the water from freezing) around a loop of pipe – called a ground loop – which is buried in your garden or land outside your property. When the liquid travels around the loop it absorbs heat from the ground – used to heat radiators, underfloor heating systems and even hot water. 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. Normally the loop is laid flat in trenches about two metres deep, but if there is not enough space in your garden you can install a vertical loop to a depth of up to 100 metres. The efficiency of a ground source heat pump is measured by a coefficient of performance (CoP) – the amount of heat it produces compared to the amount of electricity needed to run it. A typical CoP for a ground source heat pump is around 3.7.

Once inside the pump, the heat sourced from the ground is run over an evaporator or heat exchanger which works like a refrigerator in reverse to amplify the heat – making it hot enough to produce boiling water in your taps and generate enough heat to keep your whole property warm and dry.

What are the benefits of having a Ground Source Heat Pump installed?

Ground Source Heat is a renewable and inexhaustible form of energy, meaning there are numerous environmental benefits which arise from the installation of a Heat Pump system in the home. There are also financial positives due to the efficiency of these systems and in some cases the elimination of a need to pay for conventional fuels such as oil or gas.

Who is eligible?

Ground Source Heat Pumps are best installed in new buildings or properties due to the process involved in their implementation. Retrofitting (installations into existing, older properties) are possible but can be costly and complicated by nature. They are also rather disruptive as boreholes will need to be drilled on your land meaning your garden and any structures within it (outbuildings, decking, paving) may need to be taken up.

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