Why does the car window fog up when the air conditioner is on in summer?

[MacAaron]

When the air conditioner is turned on inside the car during summer, the outside temperature is lower than the inside temperature, causing the water vapor inside the car to form many tiny water droplets. The surface of the windshield is not perfectly smooth and has many small indentations, so these tiny water droplets adhere to the windshield, which is the reason for the fogging on the glass. The air conditioning system can be used to remove the fog from the glass, whether in winter or summer. In winter, turning on the cold air conditioning can effectively remove the fog on the glass. The best method is to switch on the air recirculation mode to allow full air circulation, which speeds up the evaporation of the fog, quickly removing the condensation on the glass.