Does the BMW 5 Series have no external circulation?

Pacific Auto Network BMW 5 Series has external circulation. The speed control knob (leftmost) of BMW 5 Series fan is external circulation when it is adjusted clockwise, and internal circulation when it is rotated counterclockwise, and external circulation can supplement fresh air. The state of internal and external circulation is that the air outside the car is sucked into the car by the fan, which means that the air duct outside the car and the air duct inside the car are circulating, and the wind generated by the fan comes from outside the car. Even if the fan is not turned on, there is still airflow sucked into the car to supplement the fresh air inside.

The speed control knob (leftmost) of BMW 5 Series fan is external circulation when it is adjusted clockwise, and internal circulation when it is rotated counterclockwise, and external circulation can supplement fresh air.

The state of internal and external circulation is that the air outside the car is sucked into the car by the fan, which means that the air duct outside the car and the air duct inside the car are circulating, and the wind generated by the fan comes from outside the car. Even if the fan is not turned on, there is still airflow sucked into the car to supplement the fresh air inside. Sometimes it feels windy when the fan is turned off, because the owner has set up an external circulation. When driving in the city and encountering traffic jams, the car will be full of tail gas smell, which is caused by the use of external circulation.

In the state of internal circulation, the airflow channels inside and outside the car are closed, and there is no airflow circulation without turning on the fan. When turning on the fan, the inhaled airflow only comes from the car, forming airflow circulation inside the car. The main purpose of internal circulation is to prevent external dust and harmful gases from entering the car in time and effectively, for example, when driving through smoke, dust, odor areas or dense and compact vehicles, to prevent harmful tail gas discharged by the preceding car. Another function is to keep warm.