Modern ground source heat pump (GSHP) technology can heat homes without the need for a conventional boiler by simply moving existing heat indoors. Even in the middle of Winter heat pumps can compress energy from the environment up to useful temperatures.
Ground source heat pumps, increasingly used in combination with underfloor heating, pass a frost resistant refrigerant around a pipe loop buried outdoors. As the refrigerant passes through the loop it absorbs heat from the surrounding soil. Although the temperature change is tiny the GSHP unit is able to extract it by manipulating the refrigerant mechanically to trap and release latent heat.
Outdoors the buried heat loop pipe needs to absorb heat and should remain uninsulated but where the flow and return are close and where the pipe is above ground insulation should be applied to maximise system efficiency. Buried insulation must be able to resist moisture ingress and provide a resilient protective surface.
Complex GSHP systems, such as those in schools and hospitals, have more associated pipework in the plant room. Although heated by the ground the flow temperatures here are still below ambient and without insulation condensation can occur.
Insulation should be present in order that, in order to prevent condensation and maximise efficiency, is able to demonstrate the following attributes: