Can a car's air conditioning filter isolate the virus? Who is more powerful air conditioning filter or N95 mask?

In the morning, I read our backstage questions, and even a few of them were related to the fight against COVID-19 pneumonia. For example, "Can the filter system of our car air conditioner filter out the virus?" "Do you still need to wear a mask while driving the internal circulation in the car?" "Which is more powerful, the filter element of the car air conditioner or the N95 mask?"

OK, let's talk about this today. First of all, you must be concerned about the question: can the car air conditioner filter out the virus? Unfortunately, no. The air conditioning filtration efficiency of different vehicles varies greatly. Generally speaking, the low-price cars are poor, and the luxury cars are better. However, even the air conditioning system with excellent performance and high filtration accuracy is up to the PM2.5 standard.

What is PM2.5? It can filter out all kinds of particles with diameter greater than 2.5 microns in the air. It is natural to use it to deal with dust and pollutants in the air. Even the fearsome harmful bacteria have obvious effects. The size of bacteria is micron.

However, it will not work when it comes to viruses, because viruses are much smaller, and are basically nanoscale; For example, according to the published data, the diameter of this coronavirus is about 0.1 microns, so it is equivalent to entering the uninhabited territory when encountering PM2.5 protection. Therefore, you should wear a mask even when driving in an emergency.

So what is the filtering accuracy of N95 respirator that you can hear in this period? It is about 0.3 microns, so the filtering effect of N95 mask is far better than that of a good car air conditioning filter system. Remember to keep one in the car.

It is estimated that someone will immediately ask, you just said that the diameter of the coronavirus is about 0.1 microns, while the N95 is 0.3 microns. Isn't that impossible to completely isolate it? you 're right. Even the N95 mask can not completely isolate the virus. If it is in a polluted environment, it will only reduce the inhalation concentration of the virus. In fact, the main function of N95 mask is to isolate virus carriers in the air, such as saliva and droplets when sneezing and coughing, and dust containing viruses. According to the current published expert recommendations, these are the main transmission routes of the virus, and the probability of pure air transmission is very, very low.

What should we pay attention to when we use cars and drive?

1、 Remember to close the windows, use internal circulation, and avoid going to sections and areas with dense crowds and traffic.

2、 As I said just now, try to wear a mask when driving, at least in the urban road or traffic flow, and bear it even more.

3、 Try not to take unfamiliar passengers. If there are many people in the car, remember that everyone should wear masks for protection. The narrow and closed carriage is a high-risk infectious space.

4、 Clean and disinfect the car. If the air filter element has not been replaced for a long time, it must be replaced, and pay attention to the selection of genuine products; The interior disinfection can be wiped or sprayed with 84 liquid, but remember to dilute it in advance to avoid corrosion and damage to the interior.

Finally, of course, it is necessary to minimize unnecessary travel. The home is reliable, which also contributes to the fight against the virus.