The global situation of new coronavirus is not optimistic. There are hundreds of thousands of confirmed cases every day, and the total number of deaths has reached more than 400000. However, many people do not attach great importance to this virus and do not take good preventive measures, such as wearing masks and opening the fresh air system.
At present, N95 respirator is recognized as the best one for virus protection, so what's the difference between N95 respirator and fresh air system equipped with HEPA?
The filtration efficiency of N95 respirator for particles with aerodynamic diameter ≥ 0.3 μ m is more than 95%, and HEPA's removal efficiency for particles with diameter more than 0.3 μ m (1 / 200 of hair diameter) is more than 99.97%. Through this comparison, we can know that the fresh air system equipped with HEPA (high efficiency filter) is better than the mask in filtering requirements. So what is the actual filtration efficiency of the fresh air system equipped with HEPA? Let's take a look at the inspection report of the oxygen air Wall Mounted Fresh Air Fan.
Masks are useful for virus control and fresh air systems are also helpful. In addition, compared with the mask, the fresh air system is not only for the protection of the filter screen, but also for the purpose of increasing oxygen and discharging polluted air. Therefore, it is suggested that when the virus is serious, if the fresh air system is installed, it should be opened for 24 hours under the premise of ensuring the effectiveness of the filter screen.
However, it's not that we can be safe with the fresh air system. We should also pay attention to the following aspects:
1、 The filter screen of the fresh air system shall be replaced regularly, and the accumulated harmful substances in a long time will cause secondary pollution. If in hospitals, supermarkets and other densely populated places, secondary pollution will bring serious consequences. Therefore, after the customer purchases the fresh air system, Vtronic will definitely tell the customer to change the filter screen frequently. If it is used in hospital, it needs to be replaced within a week, so as to avoid possible cross infection.
2、 In the aspect of air distribution design of fresh air system, it is necessary to design different schemes according to different places and adopt the way of centralized return air or one supply and one return in the interval. If the scheme design is unreasonable, it will bring bad consequences. For example, we usually design positive pressure fresh air at home, while Wuhan huoshenshan hospital adopts negative pressure fresh air.
3、 If the air tightness of the fresh air system equipment is not good enough and the air mixing rate is high, the harmful gas in the room may be blown back to the room again.
In such a serious epidemic, I hope everyone will wear masks to protect themselves and their families. When isolated at home, the fresh air system must be opened to enhance indoor ventilation.