1. Thermostatic control valve
Initially, at point 4, the refrigerant is liquid and comes out of the expansion valve as wet vapor.

2. Evaporator
Due to heat absorption between point 5 and point 1, the remaining liquid refrigerant evaporates under constant pressure and temperature and emerges from the evaporator as dry steam.

3. Compressor
At point 1, the compressor takes in the dry refrigerant steam and compresses it. In this process, the pressure of the refrigerant steam increases and point 2 is reached.

4. Condenser
The compressed superheated refrigerant steam of point 2 is transported into the condenser. There it is desuperheated at decreasing temperatures and then condensed at constant temperatures, so that at point 4, i.e. start and end of the refrigeration cycle, the refrigerant is liquid again.