01. What is an air conditioner filter?
Air-conditioning filter, also known as air-conditioning filter element, is mainly used to filter the air entering the car from the outside in the air-conditioning system of the car, so that impurities, dust, pollen, tiny particles in the air are isolated, and the air in the car is kept clean. It's like putting "masks" on our cars.
Air conditioner filters are generally divided into three types: filter paper filter, activated carbon filter, and HEPA filter.
The filter paper type filter element is made of filter paper or non-woven fabric, which is folded to form a thickness to increase the filter area. The filter element of this material can only filter general particles, but has little effect on harmful substances such as formaldehyde and PM2.5. Most cars use this filter because it has a large air intake and is cheap.
The activated carbon filter element is a layer of activated carbon added to the filter paper material, which can absorb formaldehyde, odor and moisture. But it still has no effect on PM2.5 that is now rampant.
HEPA is a new filter element that has emerged recently. The full name is High Efficiency Particulate Air filter, which means "high-efficiency particle air filter". It filters particles with a diameter of 0.3 microns (PM0.3) and is claimed to be 99.97% efficient. To put it bluntly, HEPA is designed to deal with PM2.5 and smog.
The three types of filter elements have their own characteristics. The more functions, the more money will be spent. Car owners and friends can choose according to their own car environment.

02. How often should the air conditioner filter be replaced?
There is no one-size-fits-all answer to this question, because it is closely related to the car environment you are in. It is usually recommended to replace it every 10,000 to 20,000 kilometers or once a year. If you are in a car environment with a lot of sand, dust, smog or high humidity, it is best to use it twice a year. In summer and winter every year, replace it when the seasons change, and do it well when using hot and cold air conditioners. Don't wait until the air conditioner in the car is turned on and there is a peculiar smell before you know to replace it.
If it is not changed for a long time, the air conditioner filter will be contaminated, which will become a breeding ground for fungi and bacteria. Not only will the air volume of our air conditioner be significantly reduced, but every time you turn on the air conditioner, you may also smell an odor, which means that bacteria have begun to breed, which is harmful to the human body.

03. How to replace the air conditioner filter?
It is relatively simple to replace the air conditioner filter, and most models can find the installation position near the glove box in front of the co-pilot.
Open the glove box, remove the old filter, turn on the air volume of the air conditioner to the maximum, blow it for two or three minutes, and let it take away the residual dust inside. Then put on a new filter, and you're done, and the whole process takes about ten minutes. Car owners with strong hands-on ability can try it by themselves, or they can go to the 4S shop to replace them together during maintenance.

04. After changing the air conditioner filter, why is there still odor?
Many car owners may find that the air conditioner filter has been changed, but there is still an obvious odor every time the air conditioner is turned on. What is going on?
In fact, the air filter is only a part of the air conditioning system. In addition, there are blowers, evaporating boxes, air-conditioning pipes, etc., especially the alternating cold and heat in the evaporating box, which is easy to hide dirt, breed bacteria, molds and mites, and thus emit unpleasant odors.
Therefore, when the car air conditioner has an odor, it is best to do a thorough cleaning of the air conditioning system while replacing the air conditioner filter to purify the air from the source.