Should I Use Internal or External Air Circulation When There's an Odor in the Car?
2 Answers
You should turn on the external air circulation to replenish fresh air. Here are the relevant details: 1. External Circulation: External circulation mode uses a fan to draw outside air into the car, meaning there is airflow between the outside and inside of the vehicle. The air blown by the fan comes from outside, and even if the fan is off, air will still flow into the car while driving, providing fresh air. Sometimes, you may feel airflow even when the fan is off, which is due to the external circulation setting. However, in heavy traffic in the city, the car may fill with exhaust fumes, which is caused by using external circulation. 2. Internal Circulation: Internal circulation mode closes the airflow passage between the inside and outside of the car. Without the fan, there is no airflow circulation, and when the fan is on, the air drawn in comes only from inside the car, creating internal airflow. Internal circulation is mainly used to effectively block external dust and harmful gases from entering the car, such as when driving through areas with smoke, dust, strong odors, or dense traffic, preventing harmful exhaust from the car ahead. Another function is to maintain warmth. Use internal circulation in traffic jams.
When I'm driving and notice strange odors in the car, such as smoke, leftover food, or damp mildew smells, I immediately switch to the fresh air (outside air) mode. This draws in fresh air from outside to quickly dilute and expel the interior odors. While the recirculation mode can temporarily block external pollutants, it traps unpleasant smells inside the car, which can cause dizziness and nausea—especially unhealthy during long trips. I've also noticed many people neglect their cabin air filters; if the filter is dirty or moldy, using recirculation mode only prolongs the odor circulation. Remember to regularly clean the car interior and avoid leaving spoiled food inside. For severe odors, visit a professional shop to clean the air conditioning system. Maintaining fresh air is crucial for driving safety and mood—don't wait for an incident to take action.
