There seems to be a bit of mystique about air and ground source heat pumps and the concept for the domestic market is still quite new.  I first saw the concept of heat pumps in America over 30 years ago and it remained a bit of a mystery to me for some years. However I attended an air source heat pump course at Mitsubishi's excellent facility at Hatfield about 10 years ago and studied their air source heat pump.  

Heat pumps work on the principle of reverse refrigeration so that heat is extracted from the ambient air temperature and transferred to produce hot water, most heat pumps still work at a temperature of -20°C.  The basic operation of a heat pump is to provide a coefficient of 5:1 that means for every kW of energy you put into the heat pump it will return the equivalent of 5kW in heat output.  The maximum water temperature you can achieve with a heat pump is 55°C.  This is in fact the maximum temperature for UFH so heat pumps are ideal for underfloor heating systems.

As previously mentioned the two types of heat pumps are Air and Ground Source.  GSHP (Ground Source Heat Pump) installation is much more involved than Air Source as there is ground work that needs to be carried out either in the form of a trench for “slinky” (plastic coil) or piling for vertical heater batteries to be fitted into the ground.  Most installation are Air Source because of this but Air Source is ideal for a small property such as a bungalow and is installed outside the property.  For more information and advice please feel free to contact us.