What are they?

Ground source heat pumps are ground loops that are buried in the ground, they transfer heat from the ground into a building to provide heat and in some cases, to heat water. 

How does it work?

There are three elements to understand how ground source heat pumps work, these are:

1. Ground loop

This is where lengths of pipe are buried in the ground normally in a horizontal trench or a borehole; a borehole is a hole that is drilled into the ground to extract a core or for a building construction. The pipe is filled with a mixture of water and anti-freeze which is pumped around to absorb heat from the ground.

2. A heat pump

 A heat pump extracts heat from the ground and heats the building, it compromises of three parts:

Evaporator

Compressor

Condenser

The evaporator absorbs the heat from the fluid underground in the ground loop; the compressor moves the refrigerant round the heat pump and compresses the gaseous refrigerant to the temperature required for the heat distribution. Finally, the condenser gives heat to a hot water tank which nourishes the heat distribution.

 3. Heat distribution

 This consists of under floor heating or radiators for space heating.

Advantages

This system does not need to use any external fuel and it is designed to heat a whole building.

Disadvantages

There are certain drawbacks to this idea, for example, pollution can be generated from the national grid electricity through fossil fuel but there are measures to reduce this, you can purchase a green tariff for green electricity and the outcome is that even if you are using national grid electricity to run the compresser, then the system will produce less co2 emissions than the most efficient condensing boiler with the same output.