How to Deal with Foggy Windshield on BMW X1?

[Daisy]

Press the defogging button, turn on the air conditioning cooling (A/C) switch, set the temperature to the lowest, and turn on the external circulation to defog. Both cold and warm air can be used to defog the car glass, 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 of using warm air to defog is the same as using cold air, but it should be noted that warm air should not be used for defogging on rainy days, as it will initially worsen the fog. When the car glass fogs up, the external circulation should be turned on. The reason for car glass 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 saturated vapor pressure than the surrounding environment, causing water vapor to gather on the glass surface and form tiny water droplets, resulting in fog. Methods to defog car glass: Air Conditioning Cooling: Use the air conditioning's dehumidification function to reduce air humidity and remove fog. In summer, especially when multiple people enter the car, if the air conditioning is not turned on in time, the high humidity of the exhaled air can quickly cause the windshield to fog up. At this time, you can turn on the air conditioning to blow cold air onto the windshield, using the air conditioning's dehumidification function to quickly remove the fog. However, if the humidity is too high and the air conditioning is not effective, you can slightly open the window to quickly reduce the humidity inside the cabin. Of course, combining this with the air conditioning will yield faster results. Air Conditioning Warm Air: 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 windshield, reducing the temperature difference between the inside and outside surfaces of the glass, thereby preventing excessive fogging. 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. Spraying Anti-Fog Agents for Prevention: Spray a small amount of defogging agent on the car glass and wipe it clean to remove dirt and stains. While polishing the glass, a thin transparent protective film is formed, which effectively prevents water vapor from condensing on the glass and forming fog. This is especially useful in cold winters. Alternatives to defogging agents include dishwashing liquid, soapy water, glycerin, alcohol, or salt water. After drying, wipe off any excess with a chamois or soft dry cloth to ensure the glass remains fog-free for several days. Opening Windows for Airflow: If the fog inside the car is not 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 dissipating the fog. The principle of this method is the same as using cold air from the air conditioning. The downside of opening windows is obvious: it cannot be used in rainy or snowy weather, on highways, or when the fog is heavy. Rear Windshield Heating: Most cars have a rear windshield heating function, although the button positions may vary, the function is the same. Turn on the windshield heating switch, and the fog on the rear windshield will disappear in about a minute.

[MalachiLee]

Having driven for over a decade, I often encounter windshield fogging, especially in compact SUVs like the BMW X1. Fogging mainly occurs due to condensation caused by the temperature difference between the interior humidity and the glass. The solution is simple: first, press the defog button on the BMW's center console—the one with the fan icon—to automatically adjust the air conditioning to blow on the glass. Turn on the A/C function, set it to around 20 degrees, increase the fan speed, and direct the airflow toward the windshield. Using the external circulation mode can introduce dry outside air, quickly dehumidifying the cabin; this also works well on rainy or snowy days. Don’t forget to clean the inside of the glass, as oil film and dust can make fogging more likely. For prevention: turn off the air conditioning before parking and open the windows to ventilate for a few minutes; replace the cabin air filter regularly; and place a dehumidifier box in the car during autumn and winter. Safety first—if fogging occurs, slow down and pull over to address it promptly.