What's the name of the anti-epidemic slogan posted on the car

During the Spring Festival, a sudden epidemic changed everyone's life. On weekdays, some humble masks have become life-saving amulets and passes. Whether traveling by public transport, walking or cycling, masks have become everyone's standard equipment, and even qualified car companies have begun to switch to masks across borders.

Among all kinds of masks, N95 mask can filter particles with a diameter of ≥0.3 micron up to more than 95%, while the size of droplets, the main carrier of novel coronavirus, is 1- 10 micron. N95 mask has become the most effective protective artifact, and one mask is hard to find.

Of course, for car owners, when traveling, they are worried that viruses in the outside air may invade the car, thus avoiding the trouble of wearing masks in the car. Their car had better have a pair of "N95 masks" to protect the family inside.

In business, marketers should seize the cusp of social hotspots. It can be seen that many car companies keep in line with the epidemic situation and publicize that their air-conditioning systems have reached N95 mask level protection. Car companies have to mass-produce "all-round anti-virus cars" within 20 days to protect users' healthy travel. However, after careful study, it is found that most of them are "high-specification and high-barrier air conditioning filter element+in-vehicle air purification device+environmental protection interior materials".

So how can vehicles effectively filter (isolate) viruses? Whether it is effective or not depends on the filtering effect of automobile air conditioning filter element. The car is a relatively closed and independent space, which mainly exchanges air with the outside through the air conditioner inside the car. Of course, when you open the door and close the window, outside air can still enter the car. Under closed conditions, the air-conditioning filter element is equivalent to a mask worn on weekdays, and whether the vehicle can effectively isolate external viruses depends entirely on the filtering effect of the air-conditioning filter element.

At present, automobile air conditioning filter elements can be roughly divided into three types: ordinary filter paper filter elements, activated carbon filter elements and HEPA filter elements. Most of the air-conditioning filter elements in the original models are ordinary filter paper filter elements, which can filter large dust and pollen. Compared with ordinary filter paper, the color of activated carbon filter core is mostly dark gray, which is because activated carbon is added to ordinary filter paper, and its purpose is to adsorb PM2.5 in the air. Neither of them can achieve the effect of filtering viruses.

So can the third generation HEPA filter resist COVID-19? Popularize it first. The so-called HEPA filter element is also called HEPA high efficiency particle filter. The principle is not to block particles through very small pore size, otherwise the pressure loss is too large and the air resistance is too high. It "captures" fine particles by van der Waals force (Brownian motion and inertial motion of particles).

The filtration effect is best for particles with diameters above 0.5 micron and below 0. 1 micron, but it is relatively weak for particles with diameters between 0. 1-0.3 micron. This is why the filtration grade of HEPA takes the filtration ratio of 0.3 micron particles as the evaluation standard. Let's not say that the application fields of automobile air conditioning filter element and N95 mask are different, and the detection methods are also different. From the perspective of filtration efficiency alone, the two are not comparable.

Tesla models well-known in the industry? x？ Take the "biological and chemical weapons defense model" as an example. The filter element area of HEPA air filtration and purification system is more than 10 times that of ordinary cars. Moreover, through the good sealing of the air intake system, the fan runs at the highest speed of 1 1, forming a certain positive pressure in the car to prevent pollutants from entering. Good isolation and filtration of bacteria, viruses, particles, dust, etc. are achieved through the overall design.

Compared with the design of many traditional models, it is difficult to reach Tesla models in terms of air tightness and filter element area. Conditions of x simulation. Although it is theoretically feasible to use HEPA filter to filter novel coronavirus, the first difficulty to be overcome is how to ensure sufficient air volume of air conditioner after using HEPA filter.

Interestingly, at the moment when the whole people are fighting the epidemic, on the one hand, car companies are in full swing, and on the other hand, enterprises are being counterfeited. February 12, a tweet "CN95! China's first automobile "mask" N95 certification! "This incident caused a crazy reprint in the circle of friends.

According to the article, "As a professional third-party certification body in the domestic automobile industry, Huacheng Certification also launched the first domestic grading certification for the filtering effect of automobile air conditioning filter elements reaching N95 level, namely CN95 certification, in which C stands for automobile and N95 stands for N95 level."

"CN95 certification will pass scientific and professional tests to evaluate and grade the filtration effect of automotive air conditioning filter elements, and help consumers understand the filtration grade of the purchased products through certification marks. Moreover, during the epidemic period, Huacheng Certification promised to provide this certification service for enterprises free of charge, simplify the certification process, help enterprises to put certified products on the market for consumers in need to buy faster, and help prevent and control the epidemic! "

When the news came out, it indirectly equated N95 masks and N95 cars with viruses, but then some enterprises cracked down on fakes. Kedebao, a world-renowned supplier of automotive air-conditioning filters, questioned the reliability of Huacheng CN95 certification, which used "A2 mineral dust" as the testing medium instead of "sodium chloride aerosol" for mask testing.

Cordova also said that he has confirmed with the Secretary General of auto filter Professional Committee of China Automobile Industry Association that the N95 certification standard of this automobile "mask" is neither the automobile industry standard nor the group standard of the filter professional committee of China Automobile Association, but the standard of the testing organization's own enterprise. In the special period when the whole country is struggling to fight the epidemic, the so-called "China's first automobile" mask "N95 certification" was launched by taking advantage of people's enthusiasm for N95 masks. Just like Master Kong and Kang Shuaibo, it is very cool, completely misleading our enterprises and end users, and misleading the people.

There is no official answer as to whether the automobile has N95 protection, but it is certain that with the progress of R&D technology and the maturity of the health concept of various automobile enterprises, it will be the general trend to upgrade the comprehensive protection capability of China automobile industry in the future. As long as it is for the health of consumers and the needs of users, it is worthy of recognition.

Of course, to take a step back here, even if the vehicle really has the virus isolation function, once the potential carrier enters the compartment, no matter how carefully cleaned and disinfected before, it is futile to replace the high-standard automobile filter. Therefore, during the epidemic period, self-isolation to reduce going out is still the safest and most effective way of health. Of course, if there is an emergency trip, the car should be disinfected frequently, and a mask should be worn in the car, so multiple protections are more secure.

This article comes from car home, the author of the car manufacturer, and does not represent car home's position.