How to Turn On the Internal and External Air Circulation for BMW 3 Series Air Conditioning?
2 Answers
BMW 3 Series Air Conditioning Internal and External Circulation Button is a circle formed by three arrows. When you see this symbol, you can turn on the internal and external circulation function. Below are the methods for cleaning the air conditioning: 1. Cleaning the Air Filter: First, consult the 4S store to understand where the car's air conditioning filter is located and the disassembly method. Locate the position of the filter. The air filter is essentially a filtering screen and is not attached to any other car components. It can be gently pulled out for cleaning. When reinstalling, apply even force with your hands. 2. Cleaning the Air Conditioning Evaporator Box: 1. Spray foam evaporator cleaner into the air conditioning drain pipe. The entire spraying process takes about five to six minutes, and it takes half an hour for the cleaner to be fully absorbed in the air conditioning pipeline. The location of the car drain pipe varies depending on the model—some are directly under the car cabin, while others are beneath the engine. If you cannot locate the drain pipe, start the car air conditioning and observe where water drips under the car; this is the outlet of the drain pipe. Do not start the vehicle or turn on the air conditioning while spraying the cleaner. 2. Perform sterilization and disinfection for the air conditioning. Spray air conditioning disinfectant into the car air conditioning blower. After spraying, start the vehicle normally for 15 minutes to disinfect the air conditioning.
I understand that the BMW 3 Series' air conditioning design is quite thoughtful. The switch for recirculation and fresh air modes is right on the climate control panel—just look for the button with an arrow icon. The inward-pointing arrow indicates recirculation mode, while the outward-pointing arrow means fresh air mode. A simple press switches between the two. I often use recirculation during smog or heavy traffic to avoid inhaling polluted air, and it also heats up the cabin faster. On highways or after rain, I switch to fresh air mode to let in clean air and prevent window fogging. This design works in tandem with the automatic system—pressing the AUTO button adjusts the mode automatically—but manual operation offers more flexibility. For safety, I always remind others not to use recirculation for too long to avoid CO₂ buildup, which can cause fatigue. The controls are intuitively placed in the central console, making them easy for both new and experienced drivers to use, enhancing the daily driving experience.
