What is the principle of car air conditioning defogging?

[CatherineAnn]

Car air conditioning defogging works as follows: Air conditioning cold air defogging: This method uses the principle of reducing temperature difference. Adjusting the air conditioning to cold air can reduce the temperature difference between the inside and outside of the car, achieving the purpose of quickly removing fog. However, the biggest drawback of this method is that people inside the car will feel very cold, and in the already cold winter, blowing cold air from the air conditioning is uncomfortable. Air conditioning warm air defogging: This method uses the principle of drying the moisture inside the car with hot air. When the warm air is turned on initially, the fog inside the car will become heavier because the temperature difference between the inside and outside increases. Once the hot air dries the moisture inside the car, the fog will disappear. If this method is used, the defogging speed is slow, so be sure to use warm air defogging before driving and wait until the fog completely disappears before hitting the road.