On the afternoon of February 13, microAir, an internationally renowned supplier in auto filter, sent an open letter to the industry in auto filter, China through its official WeChat account. In the open letter, the supplier questioned the certification standard of "N95 Mask Associated Automotive Air Conditioning Filter" proposed by Huacheng Certification (Tianjin) Technology Co., Ltd. under China Automotive Technology and Research Center the day before.
According to the confirmation of auto filter Committee of China Automobile Industry Association, the N95 certification standard of this automobile "mask" is neither the automobile industry standard nor the group standard of the filter committee of China Automobile Association, but the standard of the testing organization's own enterprise. In this regard, Ke Debao believes that Huacheng Certification launched the so-called "China's first car" mask "N95 certification at this time, which is as cool as Master Kong and Kang Shuaibo, completely misleading our enterprises and end users, and misleading the people.
What's the problem?
Ke Debao pointed out that CN95 certification certified by Huacheng "can't isolate viruses as effectively as N95 masks" for two main reasons: First, the detection medium used in this certification is A2 mineral dust, and the sodium chloride aerosol used to replace masks is stealing columns and misleading; Secondly, the certification test results show that the filtration efficiency of A2 mine dust is 95%, and it can only reach about 70% when tested by sodium chloride aerosol. The actual protection effect is far from the propaganda "N95 level", which can't protect the virus at all and mislead the public.
The following is the question mark about the certification basis and Kedebao issued the day before Huacheng certification.
In order to fully prove the accuracy of his judgment, Cordova found the China standard of N95 mask-GB? 2626-20 16.
1. The mask was tested with sodium chloride aerosol, not A2 mineral dust.
GB2626-2006 Respiratory protective articles? The standard of self-priming filter type particle-proof respirator emphasizes the detection conditions of filtration efficiency: sodium chloride is used to represent non-oily particles, and KN is used to protect non-oily suspended particles (such as fog drops, smog particles and organisms generated by cough). ), DOP is used to represent oily particles, KP is used to protect non-oily and oily suspended particles (such as lampblack), and the detection medium must be sodium chloride aerosol (non-oily).
2? The efficiency measured by A2 mineral dust is much higher than that measured by sodium chloride.
The following is the filtration efficiency curve of the conventional PM2.5 dust filter. When the particle size is 0.3um, the efficiency corresponding to pneumatic diameter or optical diameter can reach 95% (the efficiency level is equivalent to the original CN95 filter), but when tested with 0.3um sodium chloride aerosol, the efficiency is only 765,438+0%, which is far from meeting the requirements of KN95 mask.
This difference is due to the fact that according to GB/T3285. 1-20 15 automobile air conditioner filter test standard, when mineral dust is sent into the test channel by high-pressure air through high-speed running brushes, friction and collision generate a lot of charges, which leads to an increase in the filtration efficiency of the filter to be tested, but this process is not found in the sodium chloride test.
Therefore, even after passing CN95 certification, the filtering efficiency of the filter screen is far from that of N95 mask, which is not enough to resist coronavirus.
3? Sodium chloride aerosol corresponds to the equivalent diameter of electromigration, not the aerodynamic diameter.
Differential electromigration analyzer (DMA) and condensed particle counter (CPC) are needed to detect sodium chloride aerosol. The detected diameter is called electromigration equivalent diameter, which is not the aerodynamic diameter detected by aerodynamic particle size analyzer or the optical diameter detected by optical particle counter.
Aerodynamic particle size spectrum analyzer can't detect the particle size of sodium chloride aerosol.
According to GB2626-2006, the median diameter of sodium chloride aerosol is 0.075um, which exceeds the analysis limit of aerodynamic particle size spectrum analyzer (the diameter of detected particles should be greater than 0.5um), so there is no aerodynamic diameter in KN95 standard.
Note *: Due to the complex and irregular shapes of aerosol particles in the air, such as flake, line and granule, the diameter of equivalent sphere is generally used to measure the size of different particles, and there are usually three common equivalent ways:
1. Electric diameter (electronic? Mobility? Diameter (Dm): If the irregular particles studied have the same velocity as the spherical particles with a diameter of Dm in the electric field, Dm is defined as the electromigration diameter of the particles studied.
2. Aerodynamic diameter (aerodynamic? Diameter (Dp): refers to the particle diameter with the same final settling velocity as the unit density ball (ρ= 1g/cm3) in the air flow with low Reynolds number. This particle diameter describes the inertial characteristics of aerosol particles. Regardless of the physical shape, size, density or composition of particles, particles with the same aerodynamic size will show the same aerodynamic properties.
3. Optical equivalent diameter (equivalent? Optics? Diameter (Deo): refers to the standard latex? Latex spheres (spheres with specific optical characteristics and very precise shapes) have the diameter of particles with equivalent optical signals. If the irregular aerosol particles studied have the same light scattering ability as spherical particles with a diameter of Deo, Deo is defined as the optical equivalent diameter of the particles studied.
Be cautious and cautious
Có rdoba is a global science and technology group with a history of 170 years. From indoor air purification to car driving, from clothing making to wound healing, Cordoba plays an important role in many fields. Its air-conditioning filter element faces both B-segment and C-segment markets. In the C-segment retail market, many of its products are hot-selling products in JD.COM Mall.
In such an international background, an industry organization recommended that air-conditioning filter elements can prevent viruses like N95 masks. At this moment, Freudenberg did not "make a fuss" but openly questioned our standards. Tourism finance believes that this is a responsible corporate behavior.
Similarly, in the process of related publicity, our car companies should also restrain this unconfirmed publicity. As a friend of an independent brand in China said, "Our research institute here saw that they invented the N95 function of air-conditioning filter element and urged us to release the communication draft, but I think this is a gimmick to bully consumers."
In fact, in the details of communicating with this friend, we can find a detail. This local car company promotes that the air-conditioning filter has N95 function, which is actually a "comparison". First of all, this wind won't last long. Really? The institute doesn't know?
Secondly, why didn't you do publicity before, but use it to amplify this function at this time? Obviously, the air conditioning filter has such a great role, and the research institute has not figured it out.
So how did the filter element of automobile air conditioner suddenly have such a big role? "Travel Finance" read the articles promoted by enterprises during this period, and roughly drew a story line.
1, the first to use the concept of in-car disinfection is the red flag brand.
65438+1On October 29th, FAW Hongqi announced that it had joined the National Engineering Laboratory to equip Hongqi vehicles with anti-virus vehicle-mounted air disinfectants. The first batch of anti-virus vehicle-mounted air disinfectants have been distributed to some "T3 Travel" red-flag vehicles in Changchun.
The disinfectant was developed by the National Engineering Laboratory of Drug Gene and protein Screening of Northeast Normal University, and can be safely used for air disinfection in automobiles.
2. Geely is the first to use the concept of N95.
This is the earliest thing that happened. On February 4th, Geely Automobile said that it would invest 370 million yuan in advance to start the research and development of "all-round health car" with virus prevention function. However, because there is no example of a production car that relies on automobile hardware and software to prevent viruses before, Geely Automobile's move undoubtedly provides a new perspective for automobile research and development, but the technical difficulties it will face and the cross-disciplinary cooperation projects it needs are unprecedented.
After that, on February 9, Geely Automobile once again said: The company will make full use of global system capabilities, integrate global R&D resources, cooperate with relevant scientific research institutions and air filter enterprises at home and abroad, set up a special project team to tackle technical problems, and develop the first truly "? N95 mask is the filter element of high-efficiency composite air conditioner in vehicle, and the industry-leading IAPS intelligent air purification system has been developed. So as to effectively block and filter bacteria and viruses from entering the car. And strive to produce products within 20 days. The first batch of products will first be equipped on the 150 Cargill donated by Geely Automobile in the epidemic area, providing healthy and safe mobile space for frontline workers in epidemic prevention and control.
According to official information, in the initial stage, Geely wants to use its "IAPS intelligent air purification system" to block and filter bacteria and viruses from entering the car. Its work is far from the use of high-efficiency composite air conditioning filter elements. In addition to the conventional step-by-step filtration of dust, harmful gases, PM2.5 particles, etc. The filtration efficiency of particle dust with a particle size of more than 0.3 micron is over 95%, especially for droplets with a diameter of more than 0.74 micron, novel coronavirus is often attached, reaching the purification effect of "N95 mask level".
It should be pointed out that Geely's "? N95 mask car is not the "all-round health car" mentioned before, but the beginning of the company's practice of "all-round health car". The publicity only emphasizes the effect that "IAPS intelligent air purification system" can achieve.
3.SAIC took the lead in using "N95" automotive air conditioning filter.
However, on February 1 1, Roewe and MG, two local brands of SAIC, proposed that their mainstream models fully covered the "N99" guarantee. It has stronger protection ability than the mainstream "N95" level on the market. Its sharp weapon is the Group's original "three-stage progressive health protection system", in which the first stage is equipped with standard "N95" high-efficiency vehicle air conditioning filter element, the second stage is equipped with negative ion generator and antibacterial and antiallergic functional layer (the sterilization rate can exceed 99.5% 1 hour after the purifier is turned on), and the third stage is equipped with UVC? LED sterilization lamp and 360 fumigation sterilization service, through ultraviolet disinfection and steam sterilization, the effective sterilization rate can reach 99.99%.
Note that in the publicity of SAIC, the mainstream "N95" high-efficiency car air conditioning filter element was used for the first time, and it was called "mainstream".
4. The follower is GAC New Energy, ignoring the focus of publicity.
Subsequently, on February 22nd, GAC New Energy, a subsidiary of GAC Group, announced in the publicity that it had successfully developed an anti-virus healthy cockpit with "Aian filtering and anti-virus integration", which had double guarantees of "super N95 filtering and anti-virus" and "remote one-click anti-virus". The cabin air conditioning filter element adopts HEPA-class international top-grade filter element, which can effectively isolate virus attached particles, and the isolation and defense efficiency of fine particles is as high as 97%, which is better than N95 mask, which is equivalent to installing a biochemical gas mask for automobile ventilation system. At the same time, users can remotely start the disinfection mode with one button through the mobile phone APP. The negative oxygen ion filtration system will quickly settle the particles and aerosols attached to the virus, while the unique heat pump air conditioning system can sterilize at a high temperature of 60 C without residue.
For the follow-up report of GAC New Energy, Lvcai thinks that the key points have been neglected. In fact, as early as 65438+1October 30th, the company announced that it plans to invest more than 500 million yuan in R&D to build the "Ai 'an Intelligent Ecological Cockpit", whose functions include air filtration, noise reduction, radiation protection, fatigue monitoring and so on. In the future, it will be equipped with more health technologies such as facial emotion recognition, vital signs detection and medical big data intelligent IOT.
It should be said that the construction of intelligent ecological cockpit can actually tell a good story about the transformation of GAC New Energy from an automobile company to a technology company, but the theme of the story is wasted.
Of course, the concept of building an intelligent ecological cockpit was not first put forward by GAC New Energy, but only followed the trend. Just as it was preparing to follow suit, the spread of COVID-19 in China was already very serious. From the very beginning, it emphasized donating this kind of car to the disaster area.
5. About the intelligent cockpit
Intelligent cockpit is not new in the development of automobile intelligence. Many automobile companies at home and abroad have put forward this concept, and multinational automobile companies such as Mercedes-Benz, BMW, Volkswagen and Ford have also shown it in the form of concept cars many times. Great Wall Motor is a representative automobile enterprise in China.
At this year's Delhi Auto Show in India, Great Wall Motor moved their "smart cockpit" to the booth, which attracted the strong attention of many Indian consumers.
abstract
Tourism Finance hopes to see China car companies put forward plans with unique ideas for the future intelligent cockpit based on the development of car networking and autonomous driving. I also hope to see an "all-round healthy car" like Geely, which will bring automobile R&D and design into a new direction.
As zhaowei, the founder of Autolab, said, no matter whether the car has the function of filtering and antivirus, with car protection, the probability of virus infection will be greatly reduced; Considering that COVID-19 mainly relies on droplet transmission, the car's protection ability is better. Now if the car is parked in a space full of viruses, whether it can protect the people inside from poisoning is worthless. Because "there is no car parked in the ward".
Now the government encourages society to drive or take public transportation to and from work during rush hours. I isolated myself from the crowd because of the car. Therefore, instead of promoting N95 protection, it is better to promote "owning your own car is the best isolation".
This is what Zhao Yi thought was "meaningful enough".
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.