Ground Source Heat Pumps
Ground source heat pumps (GSHPs) use pipes which are buried in the garden to extract heat from the ground. This heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home.
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 your garden. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump. The ground stays at a fairly constant temperature under the surface, so the heat pump can be used throughout the year.
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. If space is limited, a vertical borehole can be drilled instead.
How do ground source heat pumps work?
Energy absorbed from the sun is stored in the ground which in the UK and Ireland maintains a fairly constant temperature of about 12°C. This energy is absorbed into an antifreeze solution which then circulates in pipes buried in the ground. Heat from the ground is absorbed at low temperatures into a fluid inside a loop of pipe (a ground loop) 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 of the house.
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, the air, or water is constantly being renewed naturally.
The benefits of ground source heat pumps:
- lowers your fuel bills, especially if you replace conventional electric heating
- could lower home carbon emissions, depending on which fuel you are replacing
- no fuel deliveries needed
- 24/7 heat for your home as well as your water
- minimal maintenance requiredd
Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. You will also notice that radiators won't feel as hot to the touch as they might do when you are using a gas or oil boiler.
Air source heat pumps are becoming more popular in the UK and Ireland as they are significantly less expensive to install. This is because they don’t require any ground works and need less space, which also makes them an excellent choice for urban dwellings, flats and apartments. Water source heat pumps can also be used to provide heating in homes near to rivers, streams and lakes. Please talk to us more about this option if required.
- Your heat distribution system. Underfloor heating can be more efficient than radiators because the water doesn’t need to be so hot. If underfloor heating isn’t possible, use the largest radiators you can. We at CEI NI Ltd will be able to advise you on this.1
- Your fuel costs. You will still have to pay fuel bills with a heat pump because they are powered by electricity, but you will save on the fuel you are replacing. If the fuel you are replacing is expensive you are more likely to make a saving.
- Your old heating system. If your old heating system was inefficient, you are more likely to see lower running costs with a new heat pump.
- Using the controls. Learn how to control the system so you can get the most out of it. You will probably need to set the heating to come on for longer hours, but you might be able to set the thermostat lower and still feel comfortable. We at Heat Pumps NI will explain to you how to control the system so you can use it most effectively.