Automatic air conditioning refrigerant circuit, function - GF83.40-P-2005CW

MODEL 204.0 /2 up to model year 2008 /YoM 07 

Shown on model 204.0 

Fig 1: Identifying Refrigerant Pressure Sensor, A/C Compressor, Condenser, Evaporator And Accumulator

Courtesy of MERCEDES-BENZ USA

Function 

The A/C compressor driven by the engine compresses the gaseous refrigerant which is heated in the process. The compressed refrigerant flows through the condenser. The refrigerant's compression heat is then withdrawn on the surface of the condenser. While cooling down, the refrigerant liquefies.

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 A/C compressor takes in the refrigerant which has become gaseous due to the collection of heat and further compresses it. The refrigerant pressure sensor monitors the pressure of the refrigerant in the process.

To prevent the evaporator from icing up, if the temperature drops below a specific value at the evaporator, the A/C compressor is switched off by the automatic air conditioning control and operating unit (N22/7).