In the last year and a half, a lot has been learned about the aerosol transmission of infectious diseases. We have learned that the chances of illness spreading through the air is 15 to 20 times more likely indoors versus outdoors, and even before COVID-19 hit the scene, schools and restaurants were sadly behind the times when it comes to air filtration and sanitation standards. The introduction of these new strains has caused a lot of changes to be made, particularly in schools and restaurants, where many people are congregating on a regular basis.
So, what role do air purifiers for schools play in the plans to mitigate transmission of infectious disease?
HEPA, HEPA, HOORAY!
According to the United States Environmental Protection Agency (EPA), HEPA filters remove about 99.97% of dust, pollen, mold, bacteria and airborne germ particles up to 0.3 microns in size. This may mean that most of our schools and restaurants nationwide will need to upgrade the strength of the HEPA filters they are using in their air purifier systems, but when they do, these systems will be effective.
According to experts, the most effective way to cut down on the aerosol transmission of infectious disease is to focus on cycling the air throughout the space as quickly and as often as possible, making sure that air is passing through as strong of a filter as possible. This makes for a good case that there should be upgraded air purifiers for schools, as well as restaurants, throughout the United States.
It can also help to have as much outdoor air introduced to the indoors as you can, while taking into account the current air quality index and the health needs of the people within your space. While that can sometimes be a complicated equation, particularly in extreme cold or extreme heat, it gets easier to calculate with the right air purifier in place.
If a school or restaurant is unable to upgrade their air purifier systems to hold a strong enough HEPA filter, portable air purifiers can also be used in each room where people will be congregating on a regular basis.
Other Precautions can be Added into a Good Mitigation Plan
Having proper ventilation and quick and frequent filtered air transfer are the most important components in cutting down on aerosol transmission. In certain conditions, particularly in restaurants, UV light can be used to sanitize surfaces and indoor air. Some air purifiers combine the HEPA filter and UV light technologies into one system, creating even more protection.
Another precaution that can be used is keeping the relative humidity of the space between 40 to 60%. This can inhibit the growth and/or spread of particles, which tend to thrive in hot and humid conditions.
The Centers for Disease Control (CDC) suggests beginning the filtration process a full two hours before the building will be inhabited, and for at least two hours after everyone leaves to achieve maximum air cleaning and circulation.
What Does This all Mean?
The best option for both schools and restaurants is for them to install and use an air purifier system that combines multiple filter technologies to cycle indoor air, combined with outdoor air, as many times per hour as possible. By focusing on this technique along with introduction of UVC light technology, germ particles don’t stand a chance and students and diners can come together with much less worry.