General information about heating and ventilation (Mercedes-Benz C-Class W202)

Fresh air for heating enters the car's interior through the intake device under the windshield. The air flows around the heating radiator and is distributed through various flaps to individual nozzles. If the heating is set to "warm", the heating valves in the engine compartment open to access the heat exchanger. The heat exchanger is located in the heating radiator and is heated by hot coolant. Passing by the hot panels of the heat exchanger, the fresh air is heated and then enters the car's interior.

The temperature in the car's interior can be set in the left or right half of the interior depending on the position of the rotary control. The electronic control device in the heating device regulates the opening time of the heating valves depending on the interior temperature. There are internal temperature sensors at the back of the heat exchanger and in the service device. Thus, the temperature in the car is maintained approximately constant, regardless of the speed of the car and the outside temperature.

A four-stage heating fan is used to increase the heating power. In order for the blowing at individual stages to occur at different speeds, switching to additional resistances is provided. Thanks to them, the current supplied to the fan motor decreases, and the blowing occurs more slowly. At the highest stage of blowing speed, additional resistances are switched off.

If the heating system has an additional dust filter, dust, pollen, air pollution and other microparticles are captured. By switching, you can completely close the air access from the outside. Air regulation then occurs through a special air filter in the car's interior.