Inside the unit
Heat Pump Refrigerant Cycle
Stage (1)
The heat transfer medium inside the evaporator (the ‘refrigerant’) is colder than the heat source (the air or ground) . As the glycol (GSHP) or outside air (ASHP) Passes across the first heat exchanger (the evaporator) the liquid refrigerant absorbs the low temperature heat energy and evaporates.
Stage (2)
The vapour then flows to the compressor and is compressed. When compressed the pressure of this vapour is increased and the temperature of the vapour rises, effectively concentrating the heat, elevating the temperature.
Stage (3)
The hot vapour flows to the second heat exchanger (the condenser) where the heat is transferred into the heating distribution system. As this heat energy is transferred, vapour condenses back into a liquid.
Stage (4)
The liquid refrigerant then passes through an expansion valve reducing its pressure, this process is the exact reverse of the compression function in stage 2 and temperature decreases ready to start the whole cycle once again.
