Ground Source Heat Pump (GSHP)

Heat Pumps can be used to deliver space heating and domestic hot water in the range of 35 to 50 degrees C and are best used in conjunction with under-floor heating. The key factor for a heat pump is the coefficient of performance (CoP). This reflects the ratio of electricity supplied to heat produced. For example, a heat pump with a CoP of 3.5 would consume 1 kW (kilowatt) of electricity and output 3.5 kW of heat. The CoP reduces as the temperature output of the heat pump is increased. Therefore it is best to use the unit with the lowest temperature output possible, and ideally not with multi-occupancy dwellings as the flow temperature requirements significantly reduce the potential savings. GSHP can also be reversed to provide cooling in summer. Ground source units must be designed carefully if used to provide stored hot water: the storage facility must be pasteurized (heated up) regularly beyond to avoid legionella. Also, careful analysis of the ground as a heat source must be undertaken to ensure that there is not a net cooling of the ground.

Compared against gas central heating, GSHP can achieve CO₂ savings of 10-25  In recent years GSHPs have become an increasingly common solution for social housing in off-gas locations and in retrofit situations.