Should You Use Cold or Hot Air to Defog the Car Interior on Rainy Days?

[ZoeRose]

On rainy days, you should use cold air to defog the car interior. Here are the details: Reason: The most common method to deal with fogged windshields while driving in the rain is to turn on the air conditioner and direct it toward the front windshield. The cold air quickly disperses the fog on the glass, providing fast and direct results. This happens because the cold air creates a "cold air film" on the glass surface, preventing carbon dioxide from condensing on the glass and thus achieving a defogging effect. Note: Hot air can also defog, but if you use hot air to defog the front windshield on a rainy day, it may worsen the fogging. Right after turning on the hot air, the front windshield may immediately become like "frosted glass." Therefore, if you are driving and the windows fog up due to rain, you should not use hot air to defog.