What should I do if the windshield fogs before the car is turned on?

1, in the case of little fog, you can properly open the windows on both sides to allow air convection, thus eliminating the temperature difference on both sides of the windshield, and naturally it is difficult to form fog.

2. In case of fog in winter, you can try to turn on the outside circulation mode, or you can reduce the fog. Start the car first in winter, and when the water temperature rises to normal temperature, you can turn on the hot air system, so that there will be no fog again during driving, because the car is dry.

3. Apply glass water on the inside of the front windshield to prevent the glass from fogging. In fact, applying glass water requires the alcohol content in it. Dip the mixture with a dry towel and smear it on the inside of the glass. After drying, wipe off the water stains with a dry towel. Under normal circumstances, it can be wiped once a month.

Extended data:

Causes of glass fogging:

The reason of window fogging is "large temperature difference between internal heating and external cooling", which is only macroscopic water vapor liquefaction, and microscopic it is related to saturated air pressure. When the external temperature is high, the saturation pressure of water vapor is high, while when the glass temperature is low, the saturation pressure of water vapor decreases near the glass. When the temperature difference is large enough and the saturation pressure is low enough, water will liquefy. The closer to the glass water, the lower the saturated air pressure, and the easier the water will liquefy.

Water molecules in the air are constantly moving irregularly. When there is no temperature difference, water molecules keep hitting the glass and flying out of it. Because the lower the temperature, the slower the movement speed, so the water molecules from the hot air touch the cold glass, the movement speed slows down and can't fly out in time, while the water molecules outside keep touching the glass, so there is more and more water on the glass, and finally they converge into small drops.

Saturation pressure can be understood as the maximum amount of a certain gas (such as water vapor and alcohol vapor) that can exist in the air at a certain temperature. When the actual amount of a gas in the air is greater than this amount, it will liquefy. Glass and water are permeable, so water will fog on the glass, but mercury will not fog. Therefore, the principle of some glass defogging agents is to cover the glass surface with a waterproof film.

China News Network-Car Tips: Give you tips to solve the fogging of driving windows in winter.

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