Different types of heat Pump
Open Loop ground source
Underground water is pumped up to the surface through a borehole, around 150mm in diameter. The heat pump extracts energy from the water, which is returned to the water table via a soak-away, ditch, stream or a second borehole. Underground water remains at a constant temperature throughout the year and is more efficient than closed loop systems; back up heating is not (normally) required. |
Closed Loop ground source
This type of system uses buried pipe (a slinky) laid horizontally or vertically in trenches 1-2 metres deep to collect energy from the ground. Vertical closed loop systems can also be used but may require multiple boreholes. During extended cold periods and towards the end of winter, the energy extracted reduces as the ground temperature drops; a back up heating system is recommended. |