Why is there water vapor inside the car?
3 Answers
Water vapor inside the car is caused by a significant temperature difference between the interior and exterior of the vehicle. Relevant information is introduced as follows: The main reason for water vapor on the car windows is that the glass is in contact with the outside environment, which is cooler, causing the water vapor inside the car to condense on the glass. There are two ways to remove this fog: either increase the temperature of the glass or reduce the humidity inside the car. Adjust the air conditioning vents to the windshield setting, turn on the air conditioning, and let the compressor work to dehumidify. However, if the temperature control knob is set to the cold air setting at this time, the people inside the car will definitely feel unbearably cold, so the temperature knob can be placed in the warm air position to achieve both defogging and heating purposes.
I encountered this issue last winter while driving. The water vapor inside the car is mainly caused by external moisture entering and condensation due to the temperature difference between the inside and outside. If the window or door seals are aged or cracked, rainwater or humid air can easily seep into the cabin, forming fog on the glass when it's warm. My experience is to immediately turn on the air conditioning defogging mode and switch to external circulation to help dry the air. Not addressing this issue for a long time can lead to blurred visibility on the glass, increasing the risk of accidents, and even cause mold and odors inside the car. Usually, parking in dry environments, promptly drying the car floor after rain, and regularly checking the condition of seals and sunroofs can greatly reduce these troubles.
When driving, I noticed that water vapor in the car is mostly caused by leakage issues, such as windows not being tightly closed or worn door seal strips. Bringing in wet items like umbrellas when getting in and out of the car can also increase humidity. My suggestion is to maintain good ventilation and press the air conditioning dehumidification button for a few minutes to solve the problem. Not cleaning the foggy windshield in time is very dangerous as it obstructs the view ahead. Developing good car habits is crucial. I check my car every day to avoid major repairs.
