Using Cold Air or Hot Air for Defogging?

[AlexandraMarie]

Defogging can be achieved using both hot air and cold air. There are three methods for defogging. Cold Air Defogging: The fundamental reason for window fogging is the significant temperature difference between the inside and outside of the car—cold outside and warm inside, which causes condensation on the windows. Using cold air for defogging can quickly dry the moisture on the windshield. Therefore, for emergency defogging while driving, cold air is effective. Hot Air Defogging: When using hot air for defogging, the fog on the windows may initially become heavier, but after a while, the hot air will dry it out. Since the moisture is removed, the windows will remain fog-free for a long time, and the interior of the car will also become much warmer. Opening Windows or Using Defogging Spray: Another method is to open the car's sunroof (or windows) while driving to maintain a consistent temperature inside the car, preventing fogging. Alternatively, you can mix dish soap with water, spray it evenly on the glass, and then wipe it clean with a dry cloth. This provides long-lasting defogging without leaving any marks.