At Lewington’s we are often asked what ground source heat pumps are and how they 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. 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, or coiled 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 3.2 without any reductions for the type of distribution system.