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Photo source: the novel coronavirus pneumonia epidemic is making a tiny part of the car hot. It is the air conditioning filter element. Recently, the car announced that it has become the first enterprise in China to obtain the official certification of Huacheng Certification Center for on-board air conditioning filter products, and to replace cn95 air filter of vehicle specification level free of charge for car owners who are selling models nationwide. Subsequently, new energy, new and other enterprises also announced free upgrade and replacement of air conditioning filter elements for users. For a time, it seems that replacing the air conditioning filter element has become a must for the majority of car owners to "prevent the epidemic with hard core". However, according to a survey conducted by the reporter of the daily economic news, the free replacement of air-conditioning filter elements by some car enterprises is not for all users, nor for all cn95 air-conditioning filter elements. The upsurge in replacing air filter elements has also made some online stores "greedy". "HEPA (high efficiency air filter) air conditioning filter element in the store can not only prevent haze and pollen, but also prevent new coronavirus from entering the car," said customer service personnel of an e-commerce platform exclusive auto parts After replacing the filter element of automobile air conditioner, can it really be hard core anti epidemic? According to rough statistics, at present, there are dozens of automobile enterprises that have announced to upgrade and replace the air conditioning filter element for free. However, in the filter element specifications listed by vehicle enterprises, although most of them have the words "N95", they have different expressions. For example, Geely's "cn95 air filter of vehicle specification level", GAC trumpchi's "N95 protection capacity filter element", and "N95 air protection system". According to the different filter efficiency of automobile air conditioning filter, the cn95 certification of Huacheng Certification Center divides the result into 5 grades from low to high, namely cn60, cn70, cn80, cn90 and cn95, and the highest filter efficiency grade is cn95. It is understood that the filter grade corresponding to cn95 is for particles with aerodynamic diameter of 0.3 μ m (A2 ash for test). The filter efficiency is more than 95%. In addition, there are requirements for filter efficiency of particles with diameter of 2.5 μ m and 10 μ M. It is to grasp this point that some vehicle enterprises use the words "efficient", "brand new" to promote air conditioning filter elements. For example, the "high efficiency air conditioning filter element" of Hongqi automobile emphasizes that 95% of particles above 0.3 μ M can be blocked; the "new air purification filter element" of xinbaojun can filter particles ≥ 0.3 μ M / droplets containing bacteria or suspended solids more than 95% The novel coronavirus often has a good filtration function which is attached to droplets larger than 0.74 microns in diameter. "During the epidemic prevention and control period, the air conditioning filter element can be replaced free of charge in the store, but it is not clear whether it can achieve N95 level protection function." Zhejiang a red flag automobile 4S shop personnel told reporters. Some people think that it's hard to say whether all kinds of air conditioning filter elements launched by automobile enterprises can play a protective role. It's not ruled out that they are just marketing gimmicks of some enterprises and want to take the opportunity to attract new users. The reporter found that among the 10 car enterprises that announced free upgrade and replacement of air conditioning filter elements for users, some are for new and old users, and some are only for new users to enjoy. For example, GAC motor's official website said that the filter element technology will be upgraded free of charge for the purchase of all models of trumpchi from now on (February 16), while for the old customers who have already purchased the car, they need to spend 99 yuan to purchase a package to upgrade the air conditioning filter element. According to the first results of cn95 certification of automotive air conditioning filter issued by Huacheng Certification Center on February 21, the air conditioning filter products applied by 9 enterprises including Geely Automobile, group, Beijing, FAW car, etc. passed the certification. At present, the certification of the second batch of products is being implemented. The upsurge of replacing automobile air conditioning filter element has also stirred the hearts of shop owners on the Internet. "This HEPA high-efficiency filter element can not only block the virus, but also better than N95 level protection advertised by automobile enterprises." When the reporter asked, is there any testing data support? "Not yet," said the customer service staff of an e-commerce platform that specializes in auto parts At present, most of the air conditioning filter elements used in vehicles are divided into three types: ordinary filter paper filter element, active carbon filter element and HEPA filter element. HEPA filter element is highly praised because of the poor filterability of the first two filter elements. In the HEPA high efficiency filter element "baby details" of many online stores, the words "blocking PM2.5" and other words are often placed in a prominent position. But under the novel coronavirus pneumonia, more and more people are concerned about how to isolate the virus outside the vehicle. Reporters found that many online store customer service staff in the introduction of HEPA high-efficiency filter, will focus on the function of blocking the virus. Can the so-called HEPA filter block the virus? A technology, the HEPA screen biological and chemical weapon defense system, has been published and tested for purification. Put a vehicle in a confined space with extreme pollution level (the EPA defines "good" air quality as PM2.5 value is lower than 12 μ g / m3, and PM2.5 in the test space is up to 1000 μ g / m3), then close the model x doors and windows and open the biological and chemical weapon defense mode. Within two minutes, the air pollution level in model X was very low (below the reference level). After 12 minutes, the PM2.5 concentration in the external air of model x decreased by 40%. In addition to reducing PM2.5 concentration, vehicles equipped with HEPA filter elements have anti-virus effect. The new novel coronavirus novel coronavirus for vehicle control released by the National Engineering Laboratory of the electric vehicle of Beijing Institute of Technology shows that the blocking efficiency of HEPA filter core is larger than 0.3 micron diameter, while the diameter of the new type coronavirus is generally larger than 0.74 microns. The proposed method is effective in controlling the blocking effect of the new type of coronavirus. The diameter of the new type coronavirus is 99.97%. However, HEPA filter element needs to be replaced in time, otherwise the filtering effect may be lost. N95 grade air conditioning filter element, HEPA filter element, new air purification filter element A variety of automobile air conditioning filter elements make people dazzled. Which one should be chosen? Generally speaking, the ventilation mode of automobile air conditioning is divided into internal circulation and external circulation. In the internal circulation mode, the air flow channel inside and outside the vehicle is closed, and the fan draws air from the vehicle; in the external circulation mode, the air flow channel inside and outside the vehicle is opened, and the fan draws air from the vehicle. Whether the ventilation mode is internal circulation or external circulation, the air in the vehicle shall be purified through the air conditioning filter element. From this perspective, novel coronavirus pneumonia filter is needed, and it is necessary to replace a new air conditioning filter. Everything will be fine. Novel coronavirus can also be transmitted through contact, such as doorknobs, steering wheel, car interior decoration, etc., and different drivers will also be infected with the same vehicle for a short time. So how to do personal protection in this situation? If you are driving on an open road with only one driver on the vehicle, you can open the window without wearing a mask; if there are more than one passenger in the vehicle, you must wear a mask and open the external circulation to enhance ventilation; if you are passing through a densely populated area slowly, you must wear a mask, close the window and use the internal circulation. The proposal to novel coronavirus for vehicle control and prevention has condensed five points for prevention and control of vehicles: net, communication, courtesy, wiping and walking. Among them, clean means that people need to disinfect their hands, clothes and soles when they return to the vehicle from the epidemic area; general means that they should ventilate more; etiquette means that when there are more than one passenger in the vehicle, they should wear masks, sit in separate positions, cough and cover their nose and mouth; wiping means that the disinfection process after the vehicle is used, mainly wiping, do not spray, no open fire; line means that if they take public vehicles, they must Wear a mask all the way.