Do air filter stop viruses?

A virus is composed of a nucleic acid molecule (DNA or RNA) and a protein (Protein) or only a protein. The virus is small, measured in nanometers, and simple in structure. The minimum aperture of the HEPA filter is 0.22um, so the HEPA filter alone cannot filter viruses. However, viruses are generally adsorbed on dust particles and will not appear alone. The air purifier is a hotbed that can effectively filter out viruses - dust, so it can indirectly filter out viruses. At the same time, the activated carbon in the activated carbon filter is a kind of black porous solid carbon, with a specific surface area of 500~1700m2/g and a large pore radius>20000 nm; The radius of transition hole is 150~20000 nm; The surface area of activated carbon with micropore radius<150nm is mainly provided by micropores, which has strong adsorption performance. Therefore, the activated carbon filter can also adsorb viruses and dust.

In addition, HEPA filter is also a very good choice.

(1) Large particles (more than 10 microns): brought into the house by air flow, they will naturally fall on the ground after a long time. Even if you get into your nose, it will be blocked by nose hair. If you wake up, you will have a runny nose. The first layer of the air purifier can be intercepted by a simple filter screen.

(2) Suspended particles (0.3~1 μ m in diameter): inhalable, second-hand smoke, lampblack, exhaust gas, etc., enlarge the filter screen of the air purifier, and disordered fibers form numerous barriers. Particles blown by the blower will be stuck and intercepted by fiber materials, and the primary filter screen can be used for filtering.

(3) Small particles (less than 0.3 μ m in diameter): generally, the smallest particle dust with a diameter of 0.1 μ m or less is very small, but it is easy to block this kind of dust. It can be cleaned with the primary filter screen. The particles of 0.1~0.3 μ m are the most difficult to clean. Aerodynamic research shows that their Brownian motion is not obvious, and they basically move along a straight line by inertia, which is far smaller than the space of fiber capillary, and are easy to be missed.