Should You Use Cold or Warm Air to Defog the Car?

[DelParker]

Both cold and warm air from the car's air conditioning system can be used to remove fog. Using warm air to blow hot air onto the glass quickly raises the temperature of the front windshield, reducing the temperature difference between the inner and outer surfaces of the glass, thereby eliminating fog. Using cold air to defog is fast and direct, but prolonged use of cold air can make passengers uncomfortable. Methods to defog the car: 1. When the fog is not heavy, slightly opening both windows to allow air convection can eliminate the temperature difference on both sides of the windshield, making it difficult for fog to form. 2. Turning on the cold air can quickly remove fog in a short time. 3. Using warm air from the air conditioning can fundamentally solve the fogging problem. The fog will not return after turning off the warm air, nor will it make passengers feel colder in winter. 4. Applying a defogging agent on the windshield forms a protective film that prevents condensation.