How it works
1. A fan draws air through an evaporator. Thermal energy within the air is transferred to a liquid refrigerant causing it to change into a gas.
2. The refrigerant gas is then drawn into a compressor which increases the pressure and as a result increases the temperature.
3. A condenser (heat exchanger) then transports the hot gas refrigerant around the outside of the water tank. This heats the water inside the tank and the gaseous refrigerant reverts back into a liquid.
4. The pressure of the refrigerant is reduced as it goes through an expansion valve and returns to the evaporator for the process to start again.