How to Prevent Fogging on Car Windows?
3 Answers
Methods to prevent fogging on car windows: 1. In winter, fogging inside the car is caused by the significant temperature difference between the inside and outside. You can balance this temperature difference by intermittently opening the windows or sunroof, which lowers the interior temperature and reduces the likelihood of fogging; 2. If fog starts to form while driving, you can turn on the air conditioning in cooling mode to lower the interior temperature and minimize the temperature difference between the inside and outside of the windows, thus preventing fogging; 3. You can also use anti-fog sprays. Apply them evenly on the windows before driving to form a transparent protective film that prevents moisture inside the car from contacting the windows and forming fog.
I've encountered windshield fogging way too many times, mainly caused by temperature differences between inside and outside the car. In cold weather when there are many passengers exhaling warm air, the windshield easily fogs up. My most common solution is to preemptively activate the AC defogging function: adjust the air vents to blow toward the windshield, turn on the AC cooling and external air circulation. This works exceptionally well because air conditioning reduces air humidity. In winter, you can first use cold air for quick defogging before switching to warm air. Additionally, I've developed the habit of opening windows for two minutes before parking to allow air exchange - when cabin humidity drops, fogging is less likely next morning. Buying a commercial anti-fog spray from supermarkets is also practical; one application lasts over half a month. Remember to regularly clean the AC filter - a dirty filter significantly reduces dehumidification efficiency.
Preventing fogging actually has its tricks. The most hassle-free way is to set the air conditioning to defog mode before driving. Most cars nowadays have a dedicated defog button that automatically adjusts the airflow angle and fan speed with a single press. Set the temperature around 22°C and keep the AC on for dehumidification. Don't forget to turn on the external air circulation, otherwise, the moisture inside the car won't dissipate, and the fogging might get worse. Here's a tip of mine: Turn off the heater before parking and shutting down the engine, then open all windows for ventilation for five minutes. Wait until the temperature and humidity inside and outside the car balance before closing the windows. Pay extra attention on rainy days or after washing the car—use a dry towel to thoroughly wipe off any water on the door and window frames, otherwise, the humidity inside the car will rise immediately. It's also convenient to keep a special anti-fog cloth in the glove compartment for backup.
