How Do Air Source Heat Pumps Work?
The air source heat pump works in the same way that a common fridge does, only in reverse and is made up of an evaporator, compressor, condenser and an expansion valve.
1. The evaporators fan draws outside air pre-heated by the sun into the unit. Liquid refrigerant at a considerably lower temperature to the outside air, causes the air to give up its heat to the vaporised refrigerant.
2. The preheated vapour passes through to the compressor, where it is compressed and upgraded to a much higher pressure and temperature.
3. The hot vapour created by the compressor enters the condenser where it is surrounded by cooler water causing heat to be given up to the water, where it can be used to heat radiators or under floor heating. The cooled high pressure refrigerant returns to its liquid state.
4. The refrigerant is further cooled and its pressure reduced by passing through the expansion device, from where it returns to the evaporator to repeat the cycle.
