Which air circulation mode should be used to defog the car in winter?
3 Answers
In winter, when using warm air to defog, you can first adjust the air circulation mode to external circulation to reduce the temperature difference between the inside and outside of the car. After waiting for a few minutes, switch to internal circulation mode. Other defogging methods: Spray anti-fog agent: When using a defogging agent, the owner only needs to spray it evenly on the glass surface and then wipe it clean with a dry towel. After wiping, a protective film will remain on the glass surface, altering the surface tension of water molecules and causing fog droplets to coalesce into larger water droplets, thus not obstructing the view. This method is also applicable to other car glass, especially the side mirrors. Homemade defogging agent with dish soap: Mix dish soap with water in a ratio of 1:6, put it in a bottle, and spray and wipe it before traveling. The effect is comparable to commercially available defogging agents, but the durability is slightly poorer.
Fogging up inside the car in winter is really common, especially on cold days. I remember once when I was driving on a mountain road, the windshield suddenly fogged up completely, and I couldn't see anything, almost causing an accident. Since then, I've developed a habit: when fog appears, I always turn on the external circulation button instead of using internal circulation. Why? Because internal circulation causes the moisture inside the car to circulate repeatedly, accumulating more and making it harder to dissipate; while external circulation introduces dry, cold air from outside, reducing humidity. Set the fan to medium or high speed, combined with the defrost function of the air conditioning, and the fog will clear quickly. Also, don't forget to adjust the temperature to a comfortable level—adding warm air can help dry things out. Remember, safety first; deal with the fog promptly to avoid distractions.
As someone who enjoys tinkering with cars, I find that defogging in winter isn't actually difficult. The reason for fogging is simple: warm air and moisture from breathing inside the car condense into water droplets when they meet the cold glass. At this point, turning on the external air circulation is key because it draws in dry outside air, quickly diluting the humidity. Never use internal circulation—that just traps the moisture and makes the fog worse. In terms of operation, simply press the external circulation button or set the air conditioning to defog mode, turn up the fan speed a bit, and using the AC's cold air can also help with dehumidification. Even if it feels cold, it's better than impaired visibility. By the way, making a habit of regularly checking your air conditioning system's functions will make winter travel more worry-free.
