These are what you need to know, but may not be clear about the filter for air purifiers
One of the core of the air purifier (Filter type) is the filter.? There are many kinds of filters that can be seen by machines on the market, but these are basically the same:
1. Pre filter: it's used to protect the HEPA filter.
Usually it looks like a screen window, the gaps are clearly visible, and the material is mostly washable. It's used to block relatively large particles of dust, hair, etc., and can slightly protect the HEPA filter. It is simply removed and cleaned every month.
2. HEPA filter: it's used to absorb and intercept fine suspended particles (commonly called PM2.5 and PM0.3). The appearance is multi-folded. On one hand, it extends the air passing time. On the other hand, it can have a larger surface area in the same volume.?It's usually classified as (H11-H14). The higher the number, the higher the filtration efficiency,?but it does not mean that the efficiency of a machine is necessarily higher or lower. The HEPA color is usually white. If there is green or blue, it is usually added with antibacterial trtment on the surface.
The filter material is actually like this, intricate fibers to adhere to particles (of course, large particles will really be intercepted).
3. Activated carbon/deodorizing filter: it deals with odor pollution, odor, volatile organic compounds, or formaldehyde. There are different types, such as granular activated carbon, powder spraying, etc., and the material is not necessarily 100% activated carbon. Zeolite is also common addition.?
4. Composite filter (sandwich carbon cloth)
Some brands will directly integrate the activated carbon and HEPA two filters together. A common reason is that the activated carbon powder is sandwiched between the filter paper (carbon cloth), which can effectively treat the machine's initial treatment of gas pollution. The efficiency is increased and the wind resistance can still be kept relatively low (in other words, the CADR of the machine will be relatively high), and even the amount of activated carbon is not needed. The shortcoming is when the two are integrated together, they can only be replaced together. Usually the gas pollution absorption rate> the solid particle absorption rate, so there will be more waste of consumables.