Should the car air conditioning use internal or external circulation?
2 Answers
When you first turn on the air conditioning, you can choose internal circulation. When the temperature inside the car becomes comfortable, you can switch to external circulation. It is recommended to alternate between internal and external circulation. Here are some relevant details: 1. External circulation: External circulation brings in fresh air by using a fan to draw outside air into the car. The air channels inside and outside the car are interconnected, so even if the fan is not turned on, airflow is still drawn into the car while driving, replenishing fresh air inside. 2. Internal circulation: Internal circulation blocks polluted air by closing the airflow channels between the inside and outside of the car. Without the fan, there is no airflow circulation, and when the fan is turned on, the airflow drawn in comes only from inside the car, creating an internal airflow cycle. This effectively prevents external dust and harmful gases from entering the car.
I've been driving for over a decade and always pay attention to using the air recirculation and fresh air modes when operating the AC. When starting the AC, I always activate recirculation mode first to rapidly cool down the cabin air - it cools down especially quickly in summer, becoming comfortable within minutes. However, keeping recirculation on continuously makes the air feel stuffy, and prolonged use can cause dizziness, so I typically switch to fresh air mode after about ten minutes to introduce outside air for better ventilation. During poor air quality conditions like smoggy days or congested urban areas, I consistently use recirculation to block dust and pollution; on highways or during good weather, fresh air mode is better for preventing fatigue. By the way, avoid keeping recirculation on when parked to prevent exhaust gas buildup - safety first. Flexible switching between modes saves energy while maintaining health.
