Does turning on the AC in the car in summer cause fogging on the outside or inside?
2 Answers
In summer, car window fogging occurs on the outside of the glass. This happens because the indoor temperature is lower than the outdoor temperature, causing the hot outdoor air to come into contact with the cold glass. The water vapor in the outdoor air then condenses into tiny water droplets on the outside of the glass, resulting in fogging. You can use the car's defogging function to remove the fog. Here are some related tips: 1. Light fogging: If the fogging is minor, you can lower the fan speed, turn on the external air circulation, and set the airflow to blow directly onto the glass. The fog will dissipate after a while, although this method is slower. 2. Opening windows for air circulation: If you're driving at low speeds, you can open the windows slightly to allow air circulation. If the fogging isn't severe, opening the side windows a crack will help equalize the indoor and outdoor temperatures, causing the fog to disperse.
In summer, fogging caused by air conditioning in the car mostly occurs on the outer side of the windows. This happens because the air conditioning cools the interior temperature significantly, making the windshield cold as well. When the hot and humid outside air comes into contact with the cold glass, it condenses into tiny water droplets. I've encountered this several times while driving—once the wipers swipe, it's clear that the fog is on the outside. However, sometimes when you first get in the car, the warm air brought in by passengers can temporarily fog up the inner side of the glass, but this usually clears up after the air conditioning runs for a while. To reduce fogging, try adjusting the air vents to avoid blowing directly onto the glass or simply use the wipers to clear the outer side—both methods are quite effective.
