How to Defog the Car Windshield?
2 Answers
Methods to defog the car windshield are: 1. Open a small gap in the side windows to allow air convection between the inside and outside of the car, which naturally dissipates the fog; 2. The air conditioner's cold air can defog—turn on the car's fan and cooling switch to direct cold air onto the glass, and the fog will disperse; 3. Turn on the air conditioner's hot air, park the vehicle by the roadside, adjust the temperature to around 25 degrees, and wait until the fog on the inside of the glass is completely dried, then lower the temperature slightly. The windshield is made by sandwiching two pieces of glass together with a layer of PVC plastic in between, which gives the windshield the ability to absorb energy and dampen vibrations.
Having driven for over a decade, I frequently encounter windshield fogging, especially during humid rainy days or seasons with temperature fluctuations. My usual approach is to immediately activate the air conditioning's dehumidification function: locate the defog button (the icon resembles a fan blowing wavy lines) in the AC control panel, press it, increase the fan speed, and direct the airflow straight at the windshield. Both cold and warm air are effective, but the key is turning on the A/C switch, which quickly dehumidifies and absorbs moisture. The principle is that fog forms due to temperature differences between the inside and outside of the car causing condensation on the glass, and dehumidification addresses the root cause. Opening the windows slightly helps disperse moisture, but avoid doing so at high speeds. Prevention is also crucial—I always clean the interior glass surface thoroughly during car washes and apply anti-fog spray to create a protective layer. Keeping the car interior dry, avoiding bringing wet clothes inside, and storing umbrellas in waterproof bags are good practices. Safety comes first: if fog obstructs your view, pull over to address it instead of attempting to wipe it while driving, which can be distracting. Adopting these habits has made my trips much smoother.
