Should You Use Recirculation or Fresh Air Mode for Dehumidifying the Car Interior?
2 Answers
Use fresh air mode for dehumidifying the car interior. Recirculation mode: When the outdoor air quality is poor or heavily polluted, such as on dusty roads, in congested traffic, or near chemical plants with unpleasant odors; use recirculation to prevent outside bad air from entering the car; in summer, to quickly cool down the car interior with air conditioning, you can use recirculation mode. Fresh air mode: You can periodically turn on fresh air mode to allow fresh air into the car; when there are many passengers inside, using fresh air mode can maintain air freshness and prevent excessive humidity in the car from causing window fogging.
I've been driving for over a decade and have learned a thing or two about dehumidification. When you first turn on the AC, always use the recirculation mode to quickly reduce humidity inside the car. The principle is that the evaporator condenses water droplets during cooling, and recirculation allows the limited cabin air to be dehumidified repeatedly. Especially on rainy days when outdoor humidity is high, using fresh air mode would let moisture in, making the windshield more prone to fogging. When the humidity gauge drops to around 50%, I switch to fresh air mode for ventilation, otherwise it gets stuffy after sitting for too long. Remember to set the vents to windshield+foot mode for optimal dehumidification. For long-distance driving, switch to fresh air mode every half hour for air exchange – it's safer for driving.
