You’ll need an area of land near your home where you can dig trenches or drill boreholes.
Digging trenches for a ground loop
If you have enough space, you can have a ground loop system. The ground needs to be suitable for digging and accessible to machinery from a road entrance. The area should have no trees, as roots will cause problems when digging trenches.
The length of ground loop and trenches depend on the size of your home and the amount of heat you need. For a newbuild three-bedroom house, expect two trenches of 30-40 metres in length. If your home is larger or is an older property that isn’t as well insulated, you’ll need a bigger ground loop.
Boreholes
If space is limited, it may be possible to drill vertical boreholes to gather heat. This is usually more expensive than digging trenches and usually needs a specialist ground (thermogeological) survey. The ground is generally warmer the deeper you dig, so these systems can be more efficient than ground loop systems.
Larger houses may need more than one borehole. A borehole is only about 20cm wide, but somewhere between 75 and 200 metres deep. The depth of the borehole depends on the heat demand of your home and the underlying geology near your home.
Inside the house
You’ll need space inside your home for the indoor heat pump unit. The inside unit often contains the hot water cylinder and is roughly the size of an American-style fridge (about 120cm x 60cm x 60cm).
