What are the key physical changes that refrigerant undergoes in the refrigeration cycle?

The refrigerant undergoes several physical changes within the refrigeration cycle, including evaporation, compression, condensation, and expansion. In the evaporator, the refrigerant absorbs heat and changes from a cool, low-pressure mixture of liquid and vapor to a warm, high-pressure vapor. The refrigerant then passes through the compressor, where its pressure and temperature increase. In the condenser, the refrigerant releases heat and condenses back into a liquid. Finally, the refrigerant expands through an expansion valve, reducing its pressure and temperature before entering the evaporator again. These physical changes dictate the demands that the piping design must meet.