What to Do When the Outside of the Windshield Fogs Up?
2 Answers
When the outside of the windshield fogs up, here are several solutions: 1. Open the windows for air circulation. If the fogging is mild, slightly open both side windows to allow air exchange inside and outside the car. The fog will dissipate when the interior temperature approaches the outside temperature. However, this method is only suitable when the car is moving at low speeds. 2. Lower the fan speed and turn on the external air circulation, then set the airflow to fully blow onto the windshield. This method is slower in defogging and is only suitable for mild fogging. 3. Mix a defogging solution with dish soap and water in a ratio of about 1:10, then apply it to the glass with a cloth. This not only defogs quickly but is also cost-effective. If dish soap is unavailable, windshield washer fluid can also help. 4. If the fog is heavy and neither opening windows nor using wipers works, adjust the air conditioning to warm air, increase the temperature, and direct all airflow to the windshield. The fog will disappear quickly with very noticeable results.
I remember one time after it rained, I drove out and suddenly the windshield fogged up outside, blurring my vision instantly, which was quite dangerous. I quickly used the windshield wipers to swipe a few times, and the fog reduced a bit, but it didn’t last. Then I turned on the car’s air conditioning, set it to dehumidify mode (that’s the setting where the fan icon points to the windshield), adjusted the temperature to cool air—avoid using hot air because it can make the outside more humid. It cleared up quickly. The principle is that the air conditioning’s dehumidification function reduces the humidity of the external air, preventing condensation. I’ve made it a habit to switch the air circulation from recirculation to fresh air before parking, allowing the car to ventilate and disperse moisture. Also, regularly clean the windshield with glass cleaner to reduce oil buildup that attracts water droplets. If fogging happens frequently, check if the air filter is clogged—if it’s old, just replace it with a new one. These methods are simple, safe, and practical.
