
Open the windows for cross-ventilation. For vehicles with a sunroof, opening the sunroof can help balance the temperature inside and outside the car, causing the fog to disappear quickly. Turn on the external air circulation and direct the air vents toward the windows to blow cold air onto the glass, preventing moisture condensation and achieving a defogging effect. In addition to cold air, turning on the air conditioner's hot air can also help defog the windows.

I remember that fogging up on both side windows is most common while driving, especially during rainy days or winter commutes. I usually press the defog button on the car first, which typically activates the air conditioning dehumidification mode with one click, effectively drying the fog on the glass. If the fog severely affects visibility, I turn up the fan speed and direct warm or cold air toward the windows—cold air works better for dehumidification in summer. I also make sure to keep the interior dry, avoiding leaving wet umbrellas or damp clothes in the car to prevent increased humidity. Sometimes, spraying a car-specific anti-fog product on the inner glass in advance can help prevent fogging and reduce distraction risks while driving. For safety, avoid sudden braking when fogging occurs; slowing down gradually and pulling over is a safer approach.

Last winter, while driving, both side windows suddenly fogged up, which startled me, but I remained calm and handled the situation. First, I slightly opened the windows to allow air circulation and balance the temperature inside and outside the car. Then, I pressed the defogger button directly, and within seconds, the fog dissipated. I noticed that the car tends to fog up more easily when there are more passengers inside, as increased breathing raises humidity levels. Therefore, I often remind passengers not to exhale toward the windows. For regular maintenance, I periodically clean the inner surfaces of the windows to prevent oil buildup that can worsen fogging. Using the heating system to blow warm air onto the windows is also effective, especially when the temperature is set higher. Placing small desiccant packs in the door slots helps absorb moisture, preventing fogging in a cost-effective and hassle-free way.

Window fogging mainly occurs when moisture inside the car condenses into water droplets upon contact with cold glass. As a frequent driver, I use the air conditioning's dehumidification mode to quickly clear fog—the switch is usually marked with a defogging icon or similar function. Proper temperature settings are also crucial: use cool air in summer and warm air in winter (with the AC button activated for dehumidification). For prevention, opening windows while driving helps reduce humidity, and avoid leaving wet items like towels or rain gear in the car. Regularly cleaning the interior glass during car washes also helps, while applying anti-fog products provides longer-lasting results.


