What is the reason why the fog on the car windshield cannot be blown away?
1 Answers
The reason why the fog on the outside of the windshield cannot be blown away is the temperature difference between the inside and outside of the car. The temperature inside the cabin is higher than outside, causing water vapor inside the cabin to condense. Fogging on the front windshield can be divided into internal fogging or external fogging. Regardless of whether it is internal or external fogging, the main reason is that the surface temperature of the glass is lower than the air temperature, and when the air humidity is high, warm and humid air encounters the cold front windshield, releasing heat and liquefying, thereby creating fog. There are three solutions for fogging on the front windshield: 1. Use the external air circulation + direct airflow to the front windshield + increase temperature + increase fan speed + do not turn on AC: This can solve over 90% of windshield fogging. The advantage is that it does not additionally increase fuel consumption, but the disadvantage is that it may make people feel uncomfortable. 2. Turn on the AC: It doesn’t matter whether internal or external air circulation is used, adjust the temperature and fan speed appropriately, and the airflow direction can be random. This can solve almost all fogging issues. The advantage is that it is comfortable and simple, but the disadvantage is that it consumes more fuel. 3. Apply a windshield defogger or detergent to the inner windshield: This can prevent fogging for a period of time. The advantage is that you don’t need to use the heater to remove fog, but the disadvantage is that it requires proper application, may produce odors, and only works for a limited time, requiring repeated application.
