Why humidification is good for virus measures.Floor cleaning is also important -from Dyson's air environment countermeasures seminar
What is attracting much attention in the corona is to increase the quality of air in the house due to ventilation and the like.That said, what should I do, isn't there a lot of people who don't come to the end?This time, Dyson, a popular air purifier and vacuum cleaner, invited Professor Koichi Makimura of the Graduate School of Medicine and Space Environmental Medicine to hold a “Winter Indoor Air Environment Measures Seminar”.。
In the room where we live, there are various dust (fine particles), which are largely divided into "biological particles" such as mold, mites, and viruses, and "non -organic particles" such as yellow sand and exhaust gas.increase.Although the degree is different, both are harmful to health, but here we pay attention to the biological particles.It is known that mites and pollen can cause allergic diseases, and the new Corona virus, which is now a problem, is one of the biological particles.
What is worrisome when this happens is, "What is the best measures for biological particles?"Professor Makimura says, "There are almost no options other than the air purifier equipped with the HEPA filter so far."For example, the virus attached to the hand can be disinfected by alcohol, etc., but the same countermeasures are not possible for the floating virus.Spraying alcohol with a concentration that can disinfect the virus can not ignore the adverse effect on people.
According to the document announced by the Ministry of Health, Labor and Welfare on June 17, 2020, if the ideal ventilation is not possible to "open the window once every 30 minutes," the air purifier to compensate for the lack of ventilation.Is valid.Moreover, in the case of an air purifier, there is a detailed specification, such as "filtered with HEPA filter" and "the air volume is about 5 cubic meters per minute".Hepa filter is simply 0 in the normal state.3 μm particles 99.A filter with a performance that can be collected over 97 %.
Have you ever wondered, "Is an air purifier really effective?"
If you look at the product information, it may be described as "collecting 99 % or more in 30 minutes", but most of these are compliant with the performance measurement standards set by the Nippon Electric Industry Association (JEMA).Test results in the environment.In other words, it is the result of the test space created for the test.
For this reason, it was not well known how effective the air purifier was in a living space where people actually live.Professor Makimura is conducting experiments to examine the effects of air purifiers in this seedlife.
The result is the data obtained in the experiment:A room where no blue line is placed, a room where orange has a fan, and a room where gray is placed an air purifier.In the experiment, first open the window, ventilate the room, close the window, and then operate the fan and air purifier for 30 minutes.After that, open the window and ventilate.
At the start of the experiment, all rooms have more than 1,000 floating particles (dust).After the ventilation, the floating fine particles have dropped to 1000 in the room where there is an empty room and a fan with a fan, but only the room with the air purifier is reduced to around 200.。Ultra -small 0.It seems that 5 μm -sized particles have decreased by 80 %.
At the seminar, the raw data of the experimental result was also confirmed (figure below).The graph on the left changes the floating fine particle weight of the room where the fan operates for only 30 minutes.The graph on the right is a change in the floating particles in the room where the air purifier operated for only 30 minutes.The most fine 0 that can be measured.5 μm particles blue line, 1 μm particles orange, 2.5 μm of particles are displayed gray.
If you look at the graph, you can see that more small particles remain in the air.In addition, when using an air purifier, more fine particles are cleaned at a stretch.
Another thing you can see is that the larger the particles, the less detected.For example, with this graph, the particles of 5 μm or more do not appear on the graph.Large particles are easy to fall on the floor.
By the way, in a dry environment, the virus is easier to dance.The size of the virus is small at several tens to hundreds of nm (nanometer), so the falling speed is slow and it is easy to drift in the air.The fallen virus may also flutter again with the movement of people.Therefore, humidification of the room becomes important.
(Note) The size of the virus is several tens to hundreds of nm (nanometer), and the bacteria are 1 μm (micrometer) or more.1 μm = 1,000nm.The size of the influenza virus is 0.It is 1 μm (100nm).
According to Professor Makimura, fine viruses are adsorbed by water drops by increasing the humidity of the room to 50 % or more, resulting in large particles of 5 μm or more.Then, the speed of the virus falls on the floor, making it difficult for humans to suck.If the humidity is high, the floating particles will easily fall on the floor, so it is important to clean the floor with a vacuum cleaner.At the same time, if you increase the humidity, mold would easily generate, so I wanted you to be careful.
Before the expansion of the new colon virus infection, I often heard stories about "I want to buy air purifiers and humidifiers for influenza measures."However, it is difficult to explain and realize whether these measures really work and how effective it is because the virus is invisible.In this seminar, the explanation by experts and experimental data can be realized that the air purifier really works, and it was very useful.
Again, according to the Ministry of Health, Labor and Welfare, the air purifier is recommended for the "sparing of the HEPA filter" and "the air volume is about 5 cubic meters per minute".If you are interested, please check the air purifier at home.