The air purifier filter generally has a primary filter, a hepa filter, an activated carbon filter, an antibacterial filter, and the like. The thickness, fineness (mesh size) and placement position of each layer of the filter are also different, and the function and service life are also different. The primary filter is usually placed on the first floor, with the shortest life and needs to be replaced frequently; the hepa filter is usually placed on the last layer and has the longest life. The combination filter is based on the matching of the wind system, combined with the purification function requirements, the different filters are placed in sequence. A composite filter is a combination of layers of screens. The advantage of a composite screen is that it can significantly reduce manufacturing costs, but it is not economical or reasonable.
Of course, the purification effect of the air purifier does not simply look at the combination of the filter. The key is to look at the degree of sealing, the thickness and weight of the filter, and the matching of the air volume and the filter.