We all have a heat pump in our homes - it is a fridge. However, the fridge is designed to create coolant, and the by-product of cooling is heat. A fridge loses its heat from the back of the unit via small pipes into the air. A heat pump works in the same way as your fridge, but it is designed to create heat, and the by-product of heat is coolant. We pass this coolant through a series of sealed ground loops under the ground. The warmth in the ground then re-heats the coolant before it is sent back to the heat pump for the cycle to start over again. A heat pump has the same reliability as your fridge and requires no scheduled maintenance.
The heat pump has a COP (Co-efficient of Performance) of over five, which means that for every unit of electricity used, the heat pump will give out over five units of heat, giving the heat pump an efficiency rating of over 500%. For further economies, using additional equipment (see energy storage) it is possible for the heat pump system to run only at night making use of cheap rate electricity, when running costs are half price.
The heat pump can comfortably heat a swimming pool and, with the aid of a specially designed heat recovery air ventilation system, keep the pool air warm at a fraction of normal running costs.
There are two main sources and methods of extracting heat fromthe ground using heat pumps these are:-
a) a ground loop b) a geo-thermal bore hole