Should You Use Internal or External Air Circulation for Defogging in Winter Rainy Days?

[BeauDella]

Use external air circulation for defogging in winter rainy days. Apply anti-fog spray: When using a defogging spray, simply spray it evenly on the glass surface and wipe it clean with a dry towel. After wiping, a protective film will remain on the glass surface, altering the surface tension of water molecules and causing fog droplets to coalesce into larger water droplets, thus preventing obstruction of vision. This method is also suitable for other car glass surfaces, especially the exterior rearview mirrors. Homemade defogging solution with dish soap: If you forget to buy defogging spray and need a temporary solution, mixing dish soap with water is a good alternative. Combine dish soap and water in a 1:6 ratio, put it in a bottle, and spray and wipe before driving. The effect is comparable to commercial defogging sprays, though the durability is slightly less.