Should You Turn on the Cold or Hot Air Conditioning When Driving in the Rain?
2 Answers
When driving in the rain, turn on the cold air conditioning because the cold air blowing onto the windshield forms a cold film on the surface, preventing carbon dioxide from condensing on the glass and thus acting as a defogging effect. You can purchase defogging sprays or anti-fog towels at auto parts stores. Spray the defogging agent onto the interior glass surfaces and wipe it clean, which not only removes dirt but also forms a thin, transparent protective film to prevent moisture from condensing into fog on the glass. The reason for fogging on the glass is due to temperature differences and humidity, where water vapor condenses into fog when it meets cold surfaces. Common defogging methods are as follows: Air Convection Method: Lower the windows on both sides to allow air circulation inside the car, balancing the temperature inside and outside. This method is only suitable for light drizzles; heavy rain will quickly wet the interior. Cold Air Defogging Method: This involves turning on the air conditioning to quickly lower the temperature inside the car, making it suitable for emergency defogging while driving. The downside is that it can feel cold on rainy days, and front-seat passengers may catch a cold if not dressed warmly. Warm Air Defogging Method: Turn on the warm air to raise the interior temperature, drying the moisture on the glass to achieve defogging. The drawback is that the fog may initially worsen, so this method is best used before driving. External Circulation Defogging: Turn on the external circulation, adjusting the air vents to blow both the windshield and footwell or just the windshield. The downside is that while this method is simple and warmer than cold air defogging, it is not as quick and takes some time to take effect.
When driving in rainy weather, I flexibly adjust the air conditioning settings to ensure safety and comfort. The key is to first activate the A/C function, as it quickly removes fog from the windows. In rainy conditions, the high humidity can easily cause the glass to fog up if the dehumidification system isn't turned on, leading to blurred vision, which is very dangerous. Personally, I prefer to switch to warm air mode if it's cold and damp outside and I feel chilly, or choose cool air mode if the air feels stuffy after the rain or if there are many passengers in the car making it feel hot. When operating the system, don’t forget to turn on the front windshield defogger button and coordinate it with the wipers to improve overall visibility. As for fuel efficiency, avoid setting the temperature too low or too high—keeping it near room temperature is best. Moderate use of the air conditioning has little impact on fuel consumption, with safe driving being the priority. Regular maintenance of the air filter is also crucial; checking it every six months can prevent functional failures. Remember, driving in the rain carries higher risks, and improper air conditioning settings can be distracting—prioritize clear visibility.
