Should You Use Recirculation or Fresh Air Mode for Defogging on Rainy Days?

[DeOwen]

For defogging on rainy days, it is recommended to use the fresh air mode and adjust the airflow direction towards the windshield. Using fresh air mode helps expel the moisture exhaled by passengers from the vehicle, while the outside cold air is less prone to condensation. Below are scenarios where recirculation mode is advised: 1. When the outside air quality is poor with severe pollution, such as dusty roads, congested traffic, or areas near chemical plants with unpleasant odors; use recirculation to prevent contaminated air from entering the cabin. 2. During summer, to quickly cool down the interior with air conditioning, recirculation mode can be used. 3. In winter, using recirculation helps maintain warmer cabin temperatures. Below are scenarios for using fresh air mode: 1. When recirculation has been used for an extended period and opening windows is inconvenient, periodically switch to fresh air mode to allow fresh air into the cabin. 2. When there are multiple passengers in the car, fresh air mode helps maintain air freshness and prevents excessive humidity inside the cabin that could lead to window fogging.

[ClaytonDella]

As a long-distance driver, I recommend prioritizing the use of the external air circulation mode for defogging in rainy weather. When it rains heavily, the high humidity outside causes the windows to fog up due to condensation of moisture inside the car. If you use the internal air circulation mode, the moisture keeps circulating inside and doesn’t escape, causing the fog to accumulate and worsen, directly obstructing your view and increasing the risk of accidents. In such situations, the most effective method is to use the external air circulation mode to bring in fresh air while activating the air conditioning’s dehumidification function. Based on my experience, first turn on the external air circulation, press the defog button, and let the cold air blow for a while until the fog clears. Then, switch to internal air circulation as needed for comfort. Don’t take shortcuts by only using internal air circulation—safety comes first when driving in the rain. Timely defogging ensures clear visibility of the road and other vehicles, as safety is no trivial matter. I’ve seen people neglect this detail and nearly cause rear-end collisions on the highway. Additionally, regularly cleaning the car’s ventilation vents can help prevent fog buildup and keep the vehicle well-maintained.

[EllieRose]

As an ordinary person who commutes by car daily, I find it more reliable to use the external air circulation for defogging on rainy days. Although the internal circulation makes the car more airtight, it's harder to expel moisture, which can actually worsen the fogging and cause inconvenience. While using external air circulation might initially produce a bit more wind noise, the air conditioning's dehumidification quickly clears the view, saving time. My car is usually set to automatic mode, where the one-touch defog feature handles the switching between internal and external circulation effortlessly. For manual operation, I recommend using external circulation with cold air settings—just a few minutes will clear the fog, and then you can turn it off. Don’t worry about complicated controls; most cars have simple buttons to minimize mistakes. Rainy days can make people nervous, and blurred vision is dangerous, so efficient handling is key. I also suggest checking the car’s air filter to ensure it’s not clogged—regular maintenance helps. Keeping things simple and efficient makes driving much easier in gloomy weather.

[PeytonLynn]

I enjoy delving into car tips and believe that turning on the recirculation mode blindly for defogging in rainy days is not ideal. Recirculating the humid air inside the car results in slow and inefficient defogging. Instead, using the fresh air mode to draw in external air, which is then dried by the air conditioning compressor before being blown in, effectively reduces humidity and quickly dissipates fog. My method involves activating the fresh air defogging mode along with increasing the fan speed for safety priority. Technically, this approach ensures better air circulation with fewer complex adjustments, reducing hassle. Avoiding heavy rain and fog that can affect driving concentration—small details can lead to big issues. Daily driving requires practicing these points to ensure safety.