Should You Use Internal or External Air Circulation on Rainy Days?

[TessaLynn]

On rainy days, it is recommended to use the external air circulation in your car. Cold weather during rain can cause fogging on both side windows, obstructing the driver's view. Therefore, it is best to first use the external air circulation and adjust the airflow direction towards the windshield. Using external circulation helps expel the moisture exhaled by passengers from the vehicle, while the outside cold air is less prone to condensation. Important Notes: Note 1: When the outside air quality is poor or heavily polluted, such as on dusty roads, in congested traffic, or near chemical plants where there are unpleasant odors or fumes, use internal circulation to prevent the poor outside air from entering the car. Note 2: In summer, to quickly cool down the interior with air conditioning, you can use internal circulation. Note 3: In winter, using internal circulation can help keep the interior warmer.

[AmirRose]

When driving in the rain, I usually keep the air recirculation mode on to block external humidity from entering the car and prevent window fogging, which can obstruct visibility. This is especially important for me since I often drive long distances on highways. During heavy rain, I get nervous about fogging up, but switching to recirculation immediately makes the air feel drier. However, prolonged use can increase carbon dioxide levels inside the car, leading to dizziness, so I briefly switch to fresh air mode for a few minutes every half hour to let in some fresh air. Of course, remember to turn on the defogging function of the AC or simply set it to cooling mode, which works even better. During heavy rain, I also use the windshield wipers—just make sure they’re clean, or they’ll affect visibility. Safety always comes first, so test what works best for your car and driving conditions.

[NatalieLynn]

On rainy days, I usually prioritize using the air recirculation mode to prevent moisture from entering and causing the windows to fog up. Foggy windows while driving can be really scary. However, I've noticed that if the rain is light or when stopped at traffic lights frequently, switching to fresh air mode briefly to let in some outside air can be quite refreshing and prevents the cabin from getting too stuffy. Regularly, I check the cleanliness of the cabin air filter because a dirty filter reduces its effectiveness and makes fogging more likely. My advice is to adapt based on actual conditions: use fresh air mode on sunny days to bring in fresh air, and rely more on air recirculation during rainy days. A driving tip I've learned over the years is to set the temperature a bit lower with the auto air conditioning mode—it's simple and hassle-free, so don't overcomplicate it.

[ElizaLynn]

When driving in rainy weather, I mainly use the recirculation mode to keep the air inside the car circulating. This reduces the entry of external rainwater and moisture, significantly lowering the risk of fogging on the windows, especially since I often have children and elderly passengers who may feel uncomfortable. Once I switch to fresh air mode, fog tends to appear quickly, particularly at night or on highways. Regularly checking that the vehicle's humidity sensor is functioning properly is sufficient, and I keep the air conditioning set at around 25 degrees for stability. In short, the practical tip is to use recirculation mode more often in rainy weather to prevent hazards, but don’t forget to occasionally open the windows for ventilation—after all, safe driving comes first.

[OJudah]

On rainy days, I definitely choose to use the air recirculation mode because the external humidity is high, which can cause windows to fog up and obstruct vision, posing a safety hazard. Using air recirculation can quickly dry the air, and when combined with the defogging button on the air conditioning, the effect is even faster. However, I also briefly switch to external air circulation, for example, turning it on every 20 minutes, to avoid the air inside the car becoming too stale or causing fatigue. Additionally, regularly cleaning the air conditioning system prevents mold growth, which can affect health. This trick is especially useful during heavy rain seasons—don’t find it troublesome; once you get used to it, driving becomes much more stable.

[CarsonMarie]

When driving in rainy weather, I prefer to use the recirculation mode to maintain air circulation inside the car. This helps reduce the load on the air conditioning system, preventing the compressor from overworking, and also prevents external moisture from causing fogging. However, if I drive for a long time without switching to fresh air mode, the air quality inside may deteriorate. Therefore, I switch to fresh air mode for a few minutes every 15 minutes to ventilate the cabin. Combining this with setting the temperature around 25°C and turning on the AC for better dehumidification works effectively. Safety is key - rainy roads are slippery and fogging-related accidents are common. Developing this habit is both worry-free and efficient.