Can an air purifier protect you from corona-virus?

Yes, it can.

As we all know that the diameter of the new corona-virus is about 100nm. The effective HEPA in the air purifier can filter out viruses in the air at 100-300 nanometers. 

But indoors, the preventive effect cannot be guaranteed.

Why?

Strictly speaking, most air purifiers cannot directly kill the new coronavirus. Although the virus can be filtered out through the filter, the virus may survive in the filter.

Only air purifiers equipped with sterilization technologies such as ion technology and electrostatic technology can directly kill viruses.

And,  80% of the virus infection channels are spread through contact,and aerosol transmission only accounts for 20%.

What is the aerosol transmission?

The traditional respiratory-related transmission routes include droplet transmission and airborne transmission.

Droplet transmission refers to droplets (diameter > 5μm) flying from the respiratory tract of an infected person directly contacting the facial mucous of a susceptible person-short distance transmission.

Air transmission generally refers to the inhalation of particles containing pathogens by susceptible persons-long distance transmission.

With the development of detection technology, people realize that when talking, coughing or sneezing, sub-micron and super-micron particles can be detected around, and their understanding of air transmission has deepened, and the concept of aerosol (aerosol) is further proposed.

In a narrow sense, aerosol refers to smaller solid and liquid particles that can be suspended in the air.

In a word, the essence of aerosol is particles that can be suspended in the air.
Compared with the general airborne transmission, aerosols can suspend longer and drift farther.

It is like walking on the road and smelling smoke, but there is no one around. This is the aerosol of particles of several hundred nanometre formed after the burning of tobacco.

If the aerosol particles are relatively large, 10 microns to 50 microns or more, ordinary medical masks (or anti-smog masks) can block them.

If the aerosol particles are small (with a radius of less than 0.1 micron), light in weight, distributed in the high altitude (off the ground), and dispersed with the wind, this will give people the possibility of breathing.

In addition, aerosol particles have a large specific surface energy and charge. The virus is easily destroyed and the survival rate is not high.

For non-medical personnel, in real life, some viruses can enter the human body through mucous membranes only when they reach a very high order of magnitude.

Similarly, only a very small number of viruses that circulate on clothes and skin in the form of aerosols can enter the eyes, mouth and nose through the touch of the hand, and even a certain amount of the virus is unlikely to cause disease.

Very small aerosol particles can catalyze or destroy viruses, so they are harmless.

Large-diameter aerosol particles can adsorb viruses, but it can be prevented and controlled by wearing a qualified mask.

Therefore, we must pay attention to the spread of aerosol viruses, but do not panic.

So how to maximize the use of air purifiers indoors?

The air purifier is internally circulated and requires windows to be opened every day for ventilation. Open windows regularly for ventilation at least twice a day, while the air purifier can keep running.

 

Chinese Standard European Standard U.S. DOP Act
0.3 micron
Efficacy(%)
ASHRA
Standard Weight Method
Efficacy(%)
ASHRAE
Standard Colorimetry
Efficacy(%)
Coarse Filter G1

 

 <65

 

Coarse Filter

G2 65-80

 

Coarse Filter

G3 80-90

 

Medium Efficiency Filter

G4 ≥90

 

Medium Efficiency Filter

F5   40-60

 

High Efficiency Filter

F6 20-25 60-80

 

High Efficiency Filter

F7 55-60 80-90

 

High Efficiency Filter

F8 65-70 90-95

 

High Efficiency Filter

F9 75-80 ≥95

 

Sub-high Efficiency Filter

H10 >85

 

Sub-high Efficiency Filter

H11 >98

 

High Efficiency Filter-A

H12 >99.9

 

High Efficiency Filter-A

H13 >99.97

 

High Efficiency Filter-B

H14 >99.997

 

High Efficiency Filter-C

H15 >99.9997

 

High Efficiency Filter-D

H16 >99.99997

 

High Efficiency Filter-D

H17 >99.999997
Besides, we know whether the air purifier can effectively block the virus, which depends on the HEPA in the air purifier. As can be seen from the above figure, the filter has a significant difference in the filtering effect of particulate matter. The well-known HEPA 12/13 high-efficiency filter It can achieve 99.9% particle filtering effect, and the filtering effect of 0.3μm particles is even better than that of N95 masks.

For this reason, we should be equipped with air purifiers with high-efficiency filters such as HEPA 12/13, so that the virus can be continuously purified and filtered, and the spread of the virus can be reduced, especially in an environment where people gather.