Should You Use Cold or Hot Air to Defrost Your Car?
2 Answers
To defrost a car, you should use hot air. When the car windows are frosted, the safest traditional method is to preheat the car and use warm air to melt the frost. The specific steps for defrosting a car are as follows: 1. Warm up the car thoroughly to allow the engine's water temperature to rise. If there is frost on the front windshield, do not use the wipers to scrape the ice. Instead, let the car idle and wait patiently for the engine's water temperature to rise. Avoid turning on the warm air during this waiting period. 2. Direct warm air toward the front windshield. Once the engine's water temperature has risen, turn on the warm air and set it to blow upward toward the windshield at the highest setting. Keep the warm air blowing for a while, as it won't have a noticeable effect immediately. Typically, this takes 5-10 minutes. 3. Use a car cleaning cloth to wipe away the frost. Once the warm air has melted the frost on the outside of the glass, gently wipe the frost with a car cleaning cloth to speed up the melting process. The melted area will gradually expand. When wiping, press lightly on the frost to ensure it has melted before wiping. 4. Use a snow scraper if necessary. If there is both frost and snow on the car's exterior windshield or other areas, in addition to the above methods, it's best to use a snow scraper for better results.
Having run an auto repair shop for over a decade, here's my professional take on defrosting: The most reliable method is using warm air with the AC button pressed. Here's why – the heated air warms up the glass, naturally melting the frost, while the activated compressor dehumidifies to prevent window fogging. However, avoid maximum fan speed initially as rapid heating of thick ice layers may cause glass cracking. For vehicles with automatic climate control, simply press the front defroster button – the system automatically adjusts temperature. Always warm up the engine for 1 minute before operating, especially for older models where this technique shows more pronounced results.
