Heating and ventilation system — general information (BMW 3 Series E46)

1. The interior heating and ventilation system includes a four-speed electric fan, deflectors in the center and at both ends of the dashboard, as well as air ducts to the feet of the driver, front and rear passengers.

2. The control panel is located on the front panel. It controls the rotary dampers that regulate the air flow through and outside the heater. The dampers are located in the mixing chamber, where the cold and hot air flows are mixed and directed through the air ducts to different areas of the cabin.

3. Cold air enters the system through a grille in the rear of the engine compartment and passes through a cabin filter, which traps dust and debris.

4. Next, the fan drives the air into the mixing chamber and then into the air ducts. If the air requires heating, the flaps direct it into the heater radiator, which is heated by the engine coolant. The exhaust air leaves the cabin through the grilles in the rear.

5. If necessary, the access of outside air to the cabin can be stopped, then the air in the cabin begins to recirculate. This mode of operation of the system is sometimes useful, since it allows you to warm up the cabin faster and get rid of unpleasant odors from outside the car. However, it is not recommended to use this mode for a long time, since the air in the cabin stops being renewed and quickly deteriorates.

6. Some models are equipped with electrically heated front seats. The seats are heated by special conductive mats sewn into the cushions and backs of the seats. The temperature is maintained automatically and can be set at three levels, which are set by a switch on the system control panel.