Ground Source Heat Pumps And Their Environmental Impact

The purpose of a Ground Source Heat Pump  (widely called as GSHP) is to maintain an optimum temperature in a home during both the summer and winter seasons. This concept is based on the tendency of heat to flow from hotter object to a colder object when they come in contact. Using this concept (and magnifying it) a GSHP will move the existing heat from the ground beneath in to the house when the house is cold, and out of the house in to the ground when the house is hot.

How a GSHP Works:

IM000085.JPG The set up comprises of long loops of pipes buried under the soil (mostly in gardens). The length of the underground piping needed is determined based on the size of the building, a larger building requires more piping. The design of the installation will vary based on the amount of free space available, when we have very little space we will go for a vertical installation, the loops of pipes are arranged vertically and deep inside the soil. However if there is sufficient space then it is better to go for the horizontal installation. However in either cases the pipes should be buried deep enough so that the surrounding temperature is almost a constant and unaffected by seasons. The usual temperature is around 8-12 degree Celsius.

The whole set up of ground source heat pumps operates like a giant refrigerator, with a liquid like antifreeze moving through the underground pipes picking up the heat and carrying it in to the house. In the house the liquid will transfer the heat to refrigerant; the heated refrigerant will then evaporate. The evaporated refrigerant is then compressed; the compression will make it hotter. This heat is then used to heat the water supply that is used in the radiators or the underfloor water heating. The entire process is reversed during the summer season.  There are alternative systems derived from the same concept, where the pipes instead of running under soil is placed through a body of underground water.  GSHP can supply heat to multiple systems, however it cannot supply heat to multiple systems simultaneously, instead one should use values to heat multiple systems.

These are certain issues with this system. GSHPs cannot produce great amount of heat quickly therefore they should run for longer time to produce the same amount of heat. The cost associated with installing this system is relatively high and there is also a recurring expense in the form of electricity charges. However despite all these negatives this system is very ecofriendly and can reduce your carbon footprint a great deal, and over a period of time it becomes economically viable. The system will also reduce the emission of greenhouse gases.

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