GF83.40-P-2005RC Automatic Air Conditioning Refrigerant Circuit, Function

GF83.40-P-2005RC Automatic Air Conditioning Refrigerant Circuit, Function
- with CODE (580) Automatic air conditioning
- with CODE (581) Comfort automatic air conditioning

Component Identification:

Function requirements, general
^ Circuit 61
^ Air conditioning switched on

Refrigerant circuit in general
The vehicle interior is cooled via the refrigerant circuit depending on the setting at the AAC [KLA] control and operating unit (N22) (with code (580) Automatic air conditioning) or at the comfort AAC [KLA] control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning). The individual components are interconnected through lines and form a closed system.

The refrigerant circuit is comprised of the following subfunctions:
^ Function sequence, high-pressure side
^ Function sequence, low-pressure side

Function sequence, high-pressure side
The refrigerant compressor driven by the engine takes in the gaseous refrigerant and compresses it. The refrigerant is heated up intensely in the process. The refrigerant is pressed through the condenser under high pressure via a line. During this process, compression heat is absorbed from the intensely heated refrigerant. The refrigerant condenses and changes state from gaseous to liquid.
The compression heat is dissipated via the condenser surface (cooling fins).
The refrigerant flows from the condenser to the fluid reservoir via a line. While it flows through the fluid reservoir, the refrigerant is cleansed of any chemical and mechanical impurities in order to protect the subsequent components. The cleaned refrigerant flows via a feed line to the expansion valve. This ensures that the pressure on the high-pressure side is maintained.

Function sequence, low-pressure side
The expansion valve injects the refrigerant into the evaporator, where it is then evaporated due to the low pressure. During this process, the physical state of the refrigerant changes from liquid to gas.
The heat required for evaporation is taken from the ambient air. The cooled air is routed through the blower motor (A32m1) into the vehicle interior.

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 control and operating unit. The evaporator temperature is recorded by the evaporator temperature sensor.