Is it okay to keep the external air circulation on while driving on the highway?
3 Answers
It is not advisable to keep the external air circulation on while driving on the highway. Here are the specific details: Introduction: When the external air circulation is turned on, outside air enters the vehicle, keeping the interior fresh and ensuring smooth breathing for passengers. However, because outside air is continuously entering the cabin, the air conditioning compressor needs to work constantly to maintain the temperature, which consumes more fuel. Correct use of external air circulation: When driving on the highway with smooth traffic and good road conditions, you can keep the internal air circulation on for extended periods to maintain the temperature. However, it is essential to switch to external air circulation for 5 to 10 minutes within an hour to allow fresh air in and increase the oxygen level inside the vehicle. Learn to use both internal and external air circulation flexibly. For example, in situations like tunnels where the air quality is poor, you can switch to internal air circulation to effectively prevent dirty outside air from entering the cabin. Conclusion: Using either internal or external air circulation for extended periods is incorrect. The right approach is to alternate between them flexibly based on the actual situation.
It's perfectly fine to keep the external air circulation on while driving on the highway, especially during long trips. The fast-moving air outside continuously refreshes the cabin air, preventing carbon dioxide buildup that can cause drowsiness. Last month, I drove from Beijing to Qingdao with the external circulation on for four hours straight—no fogging on the windows, and the air stayed fresh. However, pay attention to the weather; switch to internal circulation in smoggy conditions or when passing areas with heavy truck exhaust. Prolonged use of external circulation may increase the AC load and slightly raise fuel consumption, but safety comes first, right? Remember to open the windows occasionally for even better ventilation.
I've been doing cross-province freight transport for years, and using the external air circulation on highways has become a habit. The biggest advantage of external circulation is preventing driver fatigue, as the continuous supply of fresh air helps keep the mind clear. Especially in summer, even with the AC set at a higher temperature, it feels cooler with external circulation compared to the stuffiness of internal circulation. However, there are two things to note: first, if there's a lot of pollen or dust outside, it can easily cause sneezing; second, on rainy days, it's necessary to use the defogging function, otherwise, the windshield can fog up easily. Actually, you don't need to use external circulation the entire time—opening the windows for a few minutes when passing through mountainous areas or less crowded roads can be just as effective.
