What Causes Fogging When the Car Air Conditioner is Turned On?

[ElleMarie]

It is mainly because the air from the air conditioner blows onto the glass, causing the glass temperature to drop too low, which leads to the condensation of high-humidity outside air on the glass surface. The solution is simple: avoid directing the air conditioner vents toward the glass. The possible reasons include: 1. Excessive indoor humidity. 2. Low airflow through the indoor evaporator: The air conditioner is essentially in a dehumidification state. If the airflow is indeed low, check whether the indoor unit filter and the back of the evaporator are too dirty. 3. Dirty return air filter of the indoor unit: Or the incorrect tilt angle of the indoor unit may cause poor air distribution. 4. Incorrect tilt angle (front-back or left-right) of the indoor unit: This may prevent the condensate water generated on the heat exchanger surface during cooling from flowing into the drain pan in time, leading to fine water droplets being blown out with the air.