Should You Use Cold or Hot Air to Defog the Car in Summer?
2 Answers
Whether to use cold or hot air to defog the car in summer depends on the specific situation. Here is a detailed explanation: 1. Cold air defogging: The root cause of window fogging is the significant temperature difference between the inside and outside of the car—cold outside and warm inside, leading to window fogging. 2. Hot air defogging: When using hot air to defog, the fog on the car windows may initially become heavier, but after a while, the hot air will dry it out. 3. Opening windows or using defogging spray: You can open the car's sunroof (or windows) while driving to maintain the same temperature inside and outside the car, preventing fogging.
In summer, I highly recommend using the air conditioning to defog the windshield. Fogging occurs due to temperature differences between the inside and outside of the car, causing moisture to condense on the glass. Using cold air defogs faster. I usually turn on the AC, lower the temperature, and direct the cold air toward the windshield, which quickly reduces humidity inside the car. Remember to switch to the fresh air mode (external circulation) to bring in dry air from outside—this typically clears the fog within 30 seconds. If you use recirculation mode (internal circulation), the fog might worsen because the moisture from passengers' breath keeps circulating. Of course, if it gets too cold after prolonged use, you can adjust the temperature back to a comfortable level—by then, the fog usually doesn’t reappear.
