How to Deal with Foggy Windows When Using Air Conditioning?

[ArielAnn]

Here are the solutions for foggy windows caused by using air conditioning in a car: 1. Open windows for air circulation: Crack open the side windows slightly to allow air convection inside the car. When the interior temperature approaches the outside temperature, the fog will dissipate. 2. Use air conditioning for defogging: Press the A/C button (which stands for air conditioning cooling), lower the temperature, activate the window defogging button, and set the fan speed to maximum. As the moisture on the window surface evaporates, the window glass temperature drops quickly, achieving the defogging effect. 3. Use defogging spray: The principle of defogging spray is to apply a layer on the windshield, forming an effective protective film.

[LeSteven]

I've been driving for many years and often encounter foggy windows, especially when the air conditioning is on, causing a significant temperature difference between the inside and outside, leading to moisture condensation on the glass that obstructs visibility. I usually start by pressing the defogging button on the AC, directing the airflow toward the windshield to let the compressor work and remove the moisture. I adjust the temperature to a moderate level—not too cold or too hot—to balance humidity. At the same time, I slightly open the windows or switch to external air circulation to introduce dry air and improve airflow. I also check if there's any accumulated water inside the car or too many passengers exhaling, as these can easily cause fogging. For prevention, I make sure to clean the car floor after parking and avoid leaving wet items inside. Safety comes first—driving with foggy windows is highly risky, and even a second's delay isn't worth it. If the fog is thick, I always clear it completely before driving to avoid accidents.

[DelCameron]

As a modern car owner, I use a quick solution for foggy windows when the AC is on: immediately press the front defrost button on the car's AC, turn the fan to maximum, and direct the airflow toward the windshield. Lower the temperature slightly to speed up dehumidification, but avoid making it too cold. Switch to external air circulation mode to prevent stale air from recirculating inside—drawing in dry outside air quickly clears the fog. I've also bought anti-fog spray, which works wonders when applied with a cloth to wipe the glass, and it's affordable on Taobao for just a few dozen yuan. Regularly maintain interior cleanliness and avoid long drives with windows down after rain. This method is simple, effective, and instantly restores clear visibility, keeping the drive relaxed and enjoyable.

[Easton]

I study automotive mechanics, and cold air fogging is a physical phenomenon—high-temperature humid air condenses when it meets cold glass. When the air conditioning is on, the large temperature difference accelerates this process, causing fog. The solution is to activate the air conditioning compressor's dehumidification function, with the airflow directed straight at the windshield area. Set the temperature within a comfortable range, avoiding extreme lows, and use the external circulation to draw in dry air for humidity removal. Check if the cabin air filter is clean, as accumulated dust can reduce dehumidification efficiency. Ventilation is also crucial—cracking a window or switching to internal circulation helps prevent moisture buildup. Understanding the principle leads to more precise operation, ensuring safe driving without wasting time.