What is the function of the condenser in a vapor-compression refrigeration system?

• A. The evaporator absorbs heat from the room.
• B. The compressor raises the pressure and temperature of the refrigerant.
• C. The receiver stores liquid refrigerant.
• D. The condenser condenses refrigerant vapor to liquid and rejects heat.

Answer: (D)

Condenser's function is to remove heat from the refrigerant and change its state from vapor to liquid. In a vapor-compression system, the compressor pushes the refrigerant to high pressure and high temperature, sending hot vapor into the condenser. There, it gives off heat to the surrounding cooling medium (air or water) and condenses into a high-pressure liquid. Some systems also subcool the liquid to a bit below the saturation temperature to improve efficiency. The liquid then proceeds to the expansion device and evaporator, where it can absorb heat and continue the cycle. The evaporator’s job is to absorb heat from the space, the compressor raises pressure and temperature, and the receiver stores liquid refrigerant—so those functions belong to other components.