You should use the fresh air mode and press the defog button, turn on the air conditioning (A/C) switch, set the temperature to the lowest, and use the fresh air mode to defog. You can use either cold or warm air to defog the car windows, but warm air is slower than cold air. The most effective method is to use cold air, which blows dry cold air directly onto the glass, preventing water vapor from condensing on the glass and achieving the purpose of defogging. The method for using warm air to defog is the same as using cold air, but it's important to note that you should not use warm air to defog on rainy days, as it will initially worsen the fogging. The reason for car window fogging: There is a certain temperature difference between the inside and outside of the car. If the temperatures inside and outside the car are different, the surface with the lower temperature will have a lower saturation vapor pressure than the surrounding environment, causing water vapor to gather on the glass surface and form tiny water droplets, resulting in fogging. Methods to defog car windows: Air Conditioning Cooling: Use the air conditioning's cooling and dehumidifying function to reduce air humidity and remove fog. In the summer, especially when multiple people enter the car and the air conditioning is not turned on in time, the high humidity of exhaled air can quickly cause the windshield to fog up. At this point, you can turn on the air conditioning to blow cold air onto the windshield, using the air conditioning's dehumidifying function to quickly remove fog from the windshield. However, if the humidity is too high and the air conditioning is not effective enough, you can slightly open a window to quickly reduce the humidity inside the cabin. Of course, you can also combine this with the air conditioning for faster results. Air Conditioning Heating: Use the method of reducing the temperature difference to remove fog. In winter, use warm air to blow hot air onto the glass, quickly raising the temperature of the windshield and reducing the temperature difference between the inside and outside surfaces of the window. This can prevent excessive fogging on the windshield in time. However, it should be noted that the rear and side windows heat up more slowly, so it takes longer to completely remove the fog. Whether the air conditioning is automatic or manual, turning it on helps with dehumidification. The temperature control should not be set to the coldest position, as this can cause the outer surface of the windshield to fog up over time. Applying Anti-Fog Spray for Prevention: Spray a small amount of defogging agent onto the car windows and wipe it clean to remove dirt and stains from the glass. While polishing the glass, a thin transparent protective film is formed on the surface, effectively preventing water vapor from condensing and forming fog. This is especially useful in cold winters. Alternatives to defogging agents include dish soap, soapy water, glycerin, alcohol, or salt water. After applying and letting it dry, use a chamois or soft dry cloth to wipe off any excess residue, which will keep the car windows fog-free for several days. Opening Windows for Airflow: If the fog inside the car is not too heavy, you can open the windows on both sides to create airflow between the inside and outside of the car, reducing the temperature difference and gradually eliminating the fog. The principle of this method is the same as using the air conditioning's cold air. However, the downside of opening windows for airflow is very obvious: it cannot be used in rainy or snowy weather, on highways, or when the fog is too heavy. Rear Window Heating: Most cars have a rear window heating function, although the button location may vary. The function is the same. Turn on the rear window heating switch, and the fog on the rear window will disappear in about a minute.
