What type of air should be blown to defog car windows?
3 Answers
In summer, the air conditioning cooling method can be used to reduce air humidity and remove fog. In winter, when there is fog on the windows, the driver should turn on the air conditioning to blow warm air, which will quickly dissipate the fog because the fog evaporates rapidly when exposed to warm air. The different scenarios and reasons for using air conditioning are as follows: Summer air conditioning cooling method: Use the air conditioning's cooling and dehumidifying function to reduce air humidity and remove fog. In summer, especially when multiple people enter the car and the air conditioning is not turned on promptly, the high humidity of exhaled breath can quickly cause the windshield to fog up. At this point, turning on the air conditioning to blow cold air toward the windshield and using the dehumidifying function can remove the fog. Winter air conditioning warm air method: Use the method of reducing the temperature difference to remove fog. In winter, blowing warm air onto the glass quickly raises the temperature of the front glass, reducing the temperature difference between the inner and outer surfaces of the window glass, which can prevent excessive fogging on the windshield. However, the rear and side windows heat up more slowly, so it takes longer to completely remove all the fog.
I've been driving a taxi for twenty years, and foggy windows are a common issue, always solved by blowing hot air. First, press the defogger button with the fan symbol, adjust the air direction to blow hot air towards the front windshield, and turn on the air conditioning compressor to reduce humidity. Fogging occurs due to the temperature difference inside and outside the car, and hot air can quickly dry the moisture, ensuring clear visibility. In cold winters, hot air works best for defogging, but in hot summers, cold air works just as well. The key is to use the correct air direction—don’t just blow air at the feet or back seats. To prevent fogging, clean the windows before driving and avoid keeping wet items in the car. Safety comes first—don’t rush to accelerate once the fog clears; make sure you can see clearly before driving.
I'm just an ordinary office worker who commutes by car daily. When the windshield fogs up, I adjust the vents to blow warm air towards the front windshield. The dehumidification function of the air conditioning is crucial—just press the defog button to handle it. If there's heavy fog, I crack open the windows for ventilation and turn off the recirculation mode to let fresh air in, balancing the humidity inside and outside so the fog clears. Cold air works too, especially in summer when the car is hot—blowing cold air removes fog faster. Don’t forget to check if the cabin air filter is clogged, as that affects airflow efficiency. In dense fog, it’s safer to pull over and address it rather than risk driving.
