What Causes Windshield Fogging?
2 Answers
Windshield fogging is caused by the temperature difference between the inside and outside of the vehicle. Below are specific solutions to address interior fogging: 1. Proper Use of the Air Conditioning System: Park the car, turn on the air conditioning, adjust the temperature control to the warm air setting, and press the defrost button. Use the warm air from the AC to dry the fog on the windshield. During defogging, switch the AC to external circulation to allow fresh air to enter the cabin. Setting the compressor and fan speed to 25°C or higher can speed up the defogging process. 2. Use Specialized Anti-Fog Products: Before each use, spray the product evenly on the window and wipe it clean to form a transparent protective film on the glass, preventing fog formation. One application can prevent fogging for about 10 to 15 days. 3. Cold and Warm Air Convection: If the fogging is not severe, slightly open the side windows to allow air convection inside the car. This will gradually equalize the interior temperature with the outside temperature, causing the fog to dissipate.
I've been driving for over 20 years, and foggy windows are a very common occurrence, especially on rainy or cold days. It's mainly caused by the temperature difference between the inside and outside of the car. The warm, humid air inside the car meets the cold glass, causing the water vapor to condense into tiny droplets that gather together to form fog. Things like using the heater in winter, not closing windows properly on rainy days, or having many passengers breathing inside can all increase humidity and make fog more likely to appear. When I was younger, I didn't understand and thought the glass was just dirty. Later, I found that turning on the air conditioner to blow on the glass could solve the problem, or using the defogging mode or slightly opening the windows for ventilation also works. I remember once when I was driving a friend to the airport during a heavy rainstorm, the fog obscured my vision to the point where I could barely see the road. Since then, I've made it a habit to turn on the air conditioner to defog before setting off. Although this issue seems minor, safety comes first—don't overlook it.
