In the last article, I said that I would discuss the protective ability of automobile air conditioning. I didn't expect to see the news that Geely invested 370 million to develop a healthy car that can isolate the virus.
When I forwarded the news to the family group, I was despised by several old people. "It turns out that your car can't prevent viruses, and hundreds of thousands of things are not as useful as my two-dollar mask."
Well, this may be the idea of most of my hometown people. I think I spent tens of thousands of dollars on a car. The car seller also insisted that this air conditioner can filter PM2.5 and pollen, so I took it for granted that it can also filter viruses.
In fact, no mass-produced car air conditioner can completely isolate the virus, even if Tesla is called "biochemical defense mode", unless you can buy the exclusive car of the President of the United States-"Army No.1", which can resist the attack of biochemical weapons and rockets.
But don't be depressed. Although it is impossible for everyone's car to prevent virus, different types of car air conditioners at different prices still have the ability to filter strong and weak viruses. Let's explain the protection level of the mask in the picture below.
First of all, you should know that car air conditioners are more advanced than ordinary sponge masks, at least it started in non-woven mask.
Ordinary filter element
The filter elements of most car air conditioners are ordinary filters. This kind of air conditioner can only filter some dust and leaves in the air, and has no other function, so it is difficult to filter impurities with a diameter less than 5 microns. Equivalent to the level of non-woven mask.
Activated carbon filter element
The upgraded air conditioner filter will add activated carbon material to the filter screen, which is thicker than the ordinary filter screen, so many people think that it is normal to replace the activated carbon filter to reduce the air output of the air conditioner. Activated carbon increases the ability of the filter element to absorb odor, and has a certain filtering effect on PM2.5 particles such as pollen and dust. It achieves the filtering effect of activated carbon mask and has no lethality to virus.
HEPA filter element
Then the next step is the more advanced HEPA (high? Efficiency? Particles? Air? Filter) filter? The filtering effect of PM2.5 is above 95%, and it can also resist most bacteria, pollen and dust. In addition to physical filtration, this filter element will also add electrostatic cotton and activated carbon to further remove dust and odor.
On the whole, this is the top means of automobile air conditioning filter element at present. Most of the vehicles on the market that claim to have pollen filtration, PM2.5 filtration and green cleaning functions are basically activated carbon or HEPA filter elements, which are matched according to the grade and price of the vehicle.
But do you think HEPA has reached the level of medical surgical mask? Still not. Because the diameter of the virus is smaller, some research reports show that the diameter of novel coronavirus is between 0.06-0. 14 micron (the research data of 3M is 0. 125 micron), so HEPA filter paper alone cannot effectively filter the virus.
Can Tesla's biochemical defense model resist viruses?
Many people may think of Tesla model? X/S's HEPA chemical and biological weapon defense mode, listening to this name should be able to defend against this virus attack.
However, I regret to tell you that I can't!
In fact, as can be seen from the name, Tesla still uses HEPA filter, but unlike ordinary vehicles, its filter (as shown below) is designed to be larger, which is about three times that of ordinary automobile filter, which means it is more efficient in purification and ventilation. From this point of view, Tesla is right to call it a high efficiency air filtration system.
In addition, Tesla models are better sealed, and the biochemical defense mode will use the fan to run quickly, and establish an appropriate amount of positive pressure in the closed compartment, which is just the opposite of the negative pressure rescue function.
As we know, negative pressure ambulance means that the air pressure inside the car is lower than the air pressure outside the car, and fresh air from the outside is forcibly sent into the car, flowing from the clean area (medical area) to the polluted area (patient area), and then sent out of the car after disinfection and filtration, thus establishing an air circulation path. Tesla's biochemical defense mode establishes a positive pressure environment in the car to prevent toxic air from entering the car. Theoretically, it has a certain effect on resisting external biochemical attacks.
In addition, HEPA is not a patent of Tesla. Geely's AQS system, BYD's PM2.5 green cleaning system and Volvo's IASQ system are all similar things, including civil airliners and household air purifiers.
Excellent method of anti-virus of medical mask
Seeing this, everyone should understand that even the most advanced car air conditioner can't achieve the anti-virus effect of 2 yuan Qian Qian medical mask. What is the coup of medical mask antivirus?
No matter N95 or medical surgical masks, the means to achieve "antivirus" depends on the "filter layer" to absorb and block particulate aerosols such as viruses, and the filter layer is mainly composed of polypropylene melt-blown ultrafine fibers (about two microns in diameter). It has to be "electret treated" to make it carry a small amount of charge, so that it can still produce electrostatic adsorption on various particles in the air under fluffy conditions.
This is why the mask can't be disinfected by boiling water or spraying alcohol, and the meltblown layer will disappear when it encounters water static electricity, thus losing its adsorption effect on the virus. Of course, ultraviolet disinfection is also not feasible, because polypropylene melt-blown materials are sensitive to heat, and after being irradiated by ultraviolet rays, the structure will be destroyed, that is, oxidative degradation, and the filtration performance will be greatly reduced.
Is it necessary to prevent virus in car air conditioning?
Having said that, in fact, the conclusion to be made here is that it doesn't matter whether the car air conditioner can be disinfected with novel coronavirus this time.
As we all know, this virus can only spread if it is attached to other aerosol carriers, such as liquid spray and droplets, and the new air outlet of automobile air conditioner is usually arranged in the engine compartment under the front windshield. At low speed, it is difficult to inhale toxic aerosols, while at high speed, it means that no one can reach around. Viruses in the air are more likely to stick to door handles and clothes than inhaled into car air conditioners.
So the correct way is to carry disinfectant spray and wet wipes with you. When you get back to the car, the first thing to do is to spray disinfection and wipe your hands, and then air conditioning circulates ventilation. Air conditioning is not as practical as wearing a mask, whether it is internal circulation or external circulation.
Of course, if you are like this big brother in Dongguan and have too many masks at home, you might as well take out a few and put them on your car air conditioner filter, which is definitely better than wearing a 1 1 layer mask. I wouldn't do such a crazy thing anyway, because I don't have a mask until now.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.