For most cars, the air passes through the air conditioning filter during the internal circulation, which is equivalent to repeated filtration. At this time, the filtration effect is the best. There are also a few car designs where the internal circulation does not pass through the filter. Activating the external circulation will be discounted.
Non-original "PM2.5 dedicated" filters can significantly improve the effect of external air intake filtration (after all, it is a one-time filtration), while the original factory effect will be discounted (I have tested this before and haven't taken screenshots yet). Internal circulation, due to repeated filtration, can achieve the same filtration effect even with the original factory filter, but it takes a bit longer, possibly taking 50% to 100% more time. At the maximum air volume setting, it only takes about one or two minutes.
Tips for severe air pollution: Although the car is designed with internal circulation and does not take in air, due to the limited sealing of the car, fresh air will still come in during driving. As long as there are not many people in the car, it generally will not cause an oxygen-deficient state. So I usually turn on the internal circulation to purify the air as soon as possible. When there are many people, the external circulation is turned on. At this time, a lower air volume will be used to slow down the rate at which the existing cleanliness is lost.
Qinghe County Dongsen Auto Parts Co., Ltd. is located in Qinghe County, Xingtai City, Hebei Province. It was established in 2024. Although the company was established a short time ago, it has more than 10 years of production experience. We are a manufacturer specializing in the production of air filters, air conditioning filters and oil filters. The filters produced by our factory serve the domestic and foreign markets and have won unanimous praise from customers in Southeast Asia, Africa, South America and other regions.
