Refrigeration cycle function - GF83.40-P-2001SX

MODEL 216.3, 221.0 /1 up to Model Year 8 

Shown on model 221.071 

Fig 1: Identifying Refrigeration Cycle Function Diagram

Courtesy of MERCEDES-BENZ USA

Function 

The refrigerant compressor driven by the engine compresses the refrigerant vapor which heats up in the process. The compressed refrigerant flows through the condenser.

The refrigerant's compression heat is then withdrawn on the surface of the condenser. The refrigerant liquefies during cooling. If cooling by the airstream is not sufficient, air is additionally drawn in by the engine and air conditioning electric suction fan with integrated control (M4/7) to cool the condenser.

When the refrigerant flows through the fluid reservoir it is cleansed of any chemical and mechanical impurities.

The liquid refrigerant passes through the expansion valve into the evaporator located in the fresh air flow.

Due to the evaporation process of the refrigerant starting in the evaporator, heat is removed from the air blowing by through the system of tubes and fins from the outside, thus cooling the air.

The air humidity carried along condenses and is led to the outside.

The air is thus dried.

The refrigerant compressor aspirates the refrigerant which has turned gaseous on account of the heat absorption and then compresses it yet again.

In the process, the refrigerant pressure sensor monitors the pressure of the refrigerant.

To prevent the evaporator from icing up, if the temperature drops below a specific value at the evaporator, the refrigerant compressor is switched off by the AAC [KLA] control unit (N22/1).