
Ground Source Heat Pumps: What Are They?
In essence, a Ground Source Heat Pump (GSHP) is a renewable energy unit that utilises a network of pipes buried under the surface of your garden to convert heat from these grounds into your home. Traditionally a GSHP system will be used to warm water for your radiators or generate heat for a underfloor heating system. It can, on occasion, be used to contribute to general facilities like heating the water that goes into your boiler. Located beneath the ground surface around your home, the earth will stay at a constant temperature. Therefore GSHP can be used all year round as an effective and efficient renewable energy source.
How Do GSHPs Work?
A GSHP will be installed into your home grounds - conventionally a back garden. The circuit is formed by pipes leading away from and then back into your home. A mixture of water and antifreeze is then pumped around this loop of piping. As the formula travels around the loop (known as a ground loop) it absorbs heat from the ground. The length of the piping will depend on how much heat you will require and other variables like the size of your home. Whether your home is big or small there are reasonable methods to ensure that a GSHP unit will work with optimum efficiency once installed. For instance, in most homes the GSHP will be laid flat, or laid in coils in trenches (approximately 2metres deep), but if your garden is relatively 'tight' for space, then a vertical installation can be deployed. This is where the pipes are installed direct down into the earth in a vertical loop to depths of up to 100 metres.
"The ground loop absorbs heat from the ground. The heat is transferred to a refrigerant by the evaporator, changing it from liquid to gas. The compressor compresses the gas, causing the temperature to rise. The condenser then transfers the heat from the hot gas to the central heating system." - Energy Saving Trust
What Are The Benefits?
The benefits of installing a GSHP system are varied and great, depending on your style of living. But there are three key points that apply to all homes:
- It will reduce your CO2 emissions: in place of a traditional oil boiler, GSHPs will save over 500kg of carbon dioxide every year.
- Rid you of Fuel Bills: these systems run solely on electricity, so gas, oil and solid fuels are made obsolete for your home.
- Reduce your electricity consumption: GSHPs are very efficient, far more efficient than using electric radiators.
Are They Suitable For My Home?
Generally speaking, GSHPs are suitable for most homes. However, there are some crucial areas that need to be considered in order to help determine whether or not they are the most effective route to renewable energy:
- Although your back garden doesn't have to be particularly large, the ground must still be suitable for installing a ground loop. Ask yourself whether it is accessible to digging machinery, or, for instance, how suitable the soil is for digging? If the garden is small and the soil is laden with concrete foundations, will you really be able to accommodate a borehole. Such practicalities are best figured in the early stages of installation in order to avoid any hidden disappointments later on.
- Make sure you'll be able to keep the heat in your home. How well insulated is your house? GSHPs produce, although carbon-friendly and consistent, low temperature heat compared to traditional furnace style boilers. Therefore, to ensure that you get the best out of your GSHP, thorough insulation is a must.
- Costs and Savings. The initial cost of installing one of these systems is quite considerable. However, grants and funding are available for eligible applicants, and will help source around 1/3 of the costs. Savings will vary with depending on the size of the home, amount of heat required etc., but a GSHP system, on average, will start your savings off at around 500kg of CO2 and £160 annually - if you're replacing an oil-fired central heating system.
Whatever your motives are for installing Ground Source Heat Pumps there are a wide range of benefits, grants and savings that, in the long run, will set the perfect temperature for your home. We recommend that you visit the Energy Saving Trust for further information.
Posted under Articles, House & Home
This post was written by Ryan Whatley on January 28, 2010
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