It’s not really something we look at very often, a lot of people are interested in it at the moment though – Geothermal heating and ground source heat pumps.
A ground source heat pump uses the heat that is stored in the ground to heat and cool your home, slightly different to the air source heat pumps we have listed on our website which use the heat that is stored in the air to heat and cool your home.
The systems can cost quite a lot to install asd as you would expect with a heat pump system it requires a little extra power to actually get the pump to run as it cannot run just off the heat in the ground, the electric that it actually uses is about 30% of the amount of power used in a traditional gas powered boiler.
There are several differnt types of heat pump but the two most commonly used are open and closed loop systems. I’ve taken this extract from another website which explains the basics between the two
The heart of the geothermal systems is the ground loop. An open-loop geothermal system uses well water as a heat source. As the water passes through it, the system extracts heat, reducing the water temperature about 5 degrees F. The water is then returned to the earth, usually by running it on the ground and letting it seep into the aquifer.
A closed-loop system extracts heat from the earth by a series of liquid-filled pipes buried in the ground. The plastic pipes are filled with water and antifreeze. The pipe used in closed loop systems is buried beneath the frost line. The pipe can also be run vertically in bored holes. A typical home will have about 2,000 running feet of pipe in the earth loop. The pipe can have a guaranteed lifetime of 50 years or more.
Generally speaking an open loop is the better of the two systems as it is cheaper to install and provides a greater heating/cooling capacity. However in many cases you are better off buying a closed loop system as it will keep all of the water contained within the pipes and reduces any chance of any contaminents getting into the water. It looks like open loop systems are simply a false economy.
Robert