Ground Source Heat Pumps are a cost effective, energy efficient, and environmentally friendly way of heating and cooling buildings.
The
earth acts as a huge thermal store absorbing 50% of the sun’s energy.
In the
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Ground source heat pumps extract this heat from the earth and pump it into a building providing space heating. The heat pumps will increase the temperature to provide a more useful output temperature of around 40–50°C. GSHPs are an extremely energy efficient technology, for every unit of energy purchased as electricity, several units of heat are delivered. |
GSHPs can be used for either space heating, domestic heating water or both. GSHP work best with low temperature heat distribution, such as underfloor heating, and some GSHPs can save you up to 50% on your water-heating bill by preheating a water tank. They can also be used for cooling in a reversible system, which is more common in offices or commercial buildings.
There are three important elements to a GSHP:
1 The ground loop, that comprises lengths of pipe buried in the ground, either in a borehole or on a horizontal trench.
2 A heat pump
3 The heat distribution system, consisting of under floor heating or radiators for space heating, and in some cases water storage for hot water supply.
Ground loops can be either horizontal or vertical. When there is plenty of land available use of horizontal loops is usually the most cost effective method. Where space is tight, vertical boreholes may be the answer. They can range from 25m to 150m deep. If regional soil conditions include extensive hard rock, a vertical installation may be the only available choice.
Horizontal installations are simpler and require lower-cost equipment, however, they require longer lengths of pipe. Vertical installations tend to be more expensive due to the increased cost of drilling versus trenching, but since the heat exchanger is buried deeper than with a horizontal system, vertical systems are usually more efficient.
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Residential properties would usually require one or two boreholes: for smaller properties only one borehole would be needed, with a thermal output of 4-6kW, while for larger properties two boreholes, with 8-12kW output. Commercial buildings such as hotels and offices would require multiple bore holes. The technology used in ground-source heating systems has very low visual impact as most of a GSHP installation is underground. Inside the house, the heat pump units are about the same size as a traditional heating and cooling unit. |
A GSHP system can be installed in a residential structure of any size, anywhere, whether it is for a single family or multiple families. GSHPs can be installed on almost any size lot: under lawns, landscaped areas, driveways, or the house itself. An existing house can be retrofitted with a GSHP using the ductwork that is already there.
Heat-pump installations are unobtrusive, noise and pollution-free, providing a pleasant environment inside & outside of the home. GSHPs have no noisy fan units and few planning restrictions apply.
GSHP has an additional advantage: they are always available whatever the weather, day or night.
Currently installed systems are making a huge difference in our environment. These systems are eliminating more than three million tons of carbon dioxide - the equivalent of taking 650,000 cars off the road. GSHP systems conserve energy and, because they move heat that already exists rather than burning something to create heat, they reduce the amount of toxic emissions into the atmosphere.
Low Carbon Buildings Programme offers a £1,200 grant regardless of the size of the system.
Links for Further Information:
http://www.heatpumpnet.org.uk/ http://www.feta.co.uk/
http://www.igshpa.okstate.edu/