How to Prevent Window Fogging When Driving in Rainy Weather?

[DeAubrey]

Press the defogging button, turn on the air conditioning cooling (A/C) switch, set the temperature to the lowest, and use the external circulation to defog. You can use either cold or warm air to defog car windows, but warm air is slower than cold air. The most effective method is to use cold air, which blows dry cold air directly onto the glass, preventing water vapor from condensing on the glass and achieving the purpose of defogging. The method for defogging with warm air is the same as with cold air, but it's important to note that warm air should not be used for defogging on rainy days, as it will initially increase fogging. Always use external circulation when defogging car windows. The reason for car window fogging: There is a certain temperature difference between the inside and outside of the car. If the temperatures inside and outside the car are different, the surface of the side with the lower temperature will have a saturated vapor pressure lower than the surrounding environment's vapor pressure, causing water vapor to gather on the glass surface and form tiny water droplets, resulting in fogging.