Which Button to Press for Foggy Windows in BMW 1 Series?

[DiKyle]

Press the defogging button, turn on the air conditioning (A/C) switch, set the temperature to the lowest, and activate the external circulation to defog. Both cold and warm air can be used to defog 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 defogging. The method for using warm air is the same as using cold air, but note that warm air should not be used for defogging on rainy days as it may initially worsen the fog. Always use external circulation when defogging car windows. The reason for foggy car windows: There is a 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 in the form of tiny droplets, forming fog. 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 summer, especially when multiple people enter the car and the air conditioning is not turned on promptly, the exhaled air has high humidity, causing the windshield to fog up quickly. At this time, you can turn on the air conditioning to blow cold air onto the windshield, using the dehumidifying function to remove the fog quickly. If the humidity is too high and the air conditioning is not effective, you can slightly open the windows to quickly reduce the humidity inside the car. Of course, combining this with the air conditioning will yield 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 glass. This can prevent excessive fogging on the windshield, but note that the rear and side windows heat up more slowly, so it will take longer to remove all the fog. Whether the air conditioning is automatic or manual, turning it on helps with dehumidification. Do not set the air conditioning temperature to the coldest position, as this may cause frost to form on the outside of the windshield over time. Spraying Anti-Fog Agents for Prevention: Spray a small amount of defogging agent on the car windows and wipe it clean to remove dirt and stains. While polishing the glass, a thin transparent protective film is formed, effectively preventing 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 saline solution. After applying, let it dry and then wipe off any excess fibers with chamois or a soft dry cloth. This 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 allowing the fog to dissipate slowly. The principle of this method is the same as using cold air from the air conditioning. The downside of opening windows for airflow is obvious: it cannot be used during rain, snow, on highways, or when the fog is heavy.