Climate control regulation, function

S83.40-4588-79

The climate control enables a pleasant interior climate for the vehicle occupants in the event of different weather conditions.

The air conditioning system (with CODE H06 (A/C)) is manually regulated and configured using the selector control integrated into the climate control operating unit switch (S98):

 Air distribution selector wheel

 Controller for temperature control

 Controller for blower control

The air conditioning system (with CODE HH9 (Semi-automatically controlled A/C, TEMPMATIC)) can be manually or automatically regulated and configured using the buttons integrated into the climate control control and operating unit.

The air circulation for the climate control is regulated via the air distribution flaps.

The temperature is controlled using the blend air and shutoff flap, which is adjusted by the blend air flap actuator motor, as well as through the A/C compressor. At "maximum heating" (temperature set to max. using the controller for temperature control) or at "maximum cooling", (temperature set to min. using the controller for temperature control) no more regulation takes place. The fresh air or the recirculated air are regulated using the fresh air or air recirculation flap. This is adjusted by the fresh air/recirculated air flap actuator motor (M2/5).

The climate control comprises the following subfunctions:

 Ventilation

 Heating circuit

 Refrigerant circuit

 Temperature control

The coolant pump circulates the coolant in the coolant circuit. Coolant always flows through the front heater heat exchanger.

Ventilation

Ventilation ensures air circulation in the vehicle interior. The user can choose between fresh air or air recirculation mode. Selection is made using the air dehumidification mode or defrosting and air recirculation mode button. The controller for the blower control and the air distribution switch are used to control the rate of circulation and the distribution of the fresh or recirculated air. The drawn in fresh air or recirculated air is distributed in the vehicle interior through the air distribution flap and the air outlets.

Heating circuit

The coolant is heated in the coolant circuit by the engine. Next, the heated coolant is supplied via the heater water feed line through the front heater heat exchanger, which delivers the heat to the air in the vehicle interior. The coolant is then returned to the coolant circuit via the heating water return.

Refrigerant circuit

The refrigerant compressor compresses the gaseous refrigerant which is heated up as a result. Next, the refrigerant vapor is forwarded to the condenser, where it cools down and thus becomes liquid (condensation). After being cleaned in the desiccant cartridge, the liquid refrigerant is forwarded to the evaporator via the restrictor. The refrigerant evaporates and cools down the blowby fresh air or recirculated air. The refrigerant compressor draws in the refrigerant again, which has become gaseous due to collection of heat.

Temperature control

The climate control function regulates the heater, the air conditioning and the ventilation depending on the position of the controller for the temperature control and blower control as well as the air distribution selector wheel, and actuates the following actuator motors:

 Fresh air/air recirculation flap actuator motor

 Blending air flap actuator motor

 Air distribution actuator motor

The controller for the temperature control is used to set the desired temperature in the vehicle interior. The position of the blend air and shutoff flap is adjusted depending on the desired temperature via the blend air flap actuator motor. The air volume of fresh air or recirculated air is thereby regulated via the heated heater core or the evaporator.