Products that filter the air either coming into a space or the air already in a space have fairly universal acceptance with air quality experts. The downside of air filtration is, and this is going to sound obvious, it only filters air moving through the filter. In other words, if viruses and particles are not being drawn into the filters, they will not have any effect. Filters can be installed in many places. Most commonly they will be in the HVAC system but portable as well as installed air filtration devices are also effective. A negative about filters is they need to be replaced on a regular basis to stay effective. Another challenge is having the right filter in place. Studies have found that filters with a MERV rating of 13 or higher are effective in capturing contaminates and viruses. HEPA filters provide the highest level of filtration with MERV16 filters being a very close second. The issue is simply adding a HEPA filter to your HAVC system or mounting it to a box fan can cause other issues. HVAC systems are usually calibrated for a MERV8 filter which is good for most pollutants but when you get down to virus level, they are not doing much. Adding a higher rated filter is going to restrict the airflow, and could cause damage to your HVAC system or considerably reduce the life of a box fan. You should consult the manufacturer for the highest rated filter you can use in your system.
As with air filters, air movement products have a universal acceptance with IAQ experts as being a good solution. As you see more and more articles citing poor ventilation as a cause, it become clear that ventilation and air movement products are good solutions. These include exhaust fans to move the “bad” air out of a space and air intake products to bring fresh air into a space to replace the “bad” air. When it comes to viruses, studies are showing you are less likely to contract a virus in outdoor spaces than indoor. A main reason is the outdoor air dilutes the viral load (concentration of viruses) to a point it is not as contagious. Exhausting air while bringing fresh air in is using this same principle – remove and dilute. With exhaust and air intake products we are now talking about an installed item so there is an upfront cost but these are also going to be some of the most effective, long term solutions. As with filters, exhaust and intake fans are only going to work if they are operating so it is important you utilize products that will run continuously providing constant air exchanges.
Ultraviolet Light Products
These products output high doses of UV light that claim to kill viruses when exposed. They can be added to the HVAC system or as their own system. Hospitals have been and continue to use UV-C to sterilize rooms. UV-C has been shown to be effective at killing viruses. The issue is the time of exposure needed to effectively kill viruses as well as the intensity. The other issue is UV – especially UV-C light is harmful to humans. Therefore it is important that these products are installed by professionals and used according to the manufacture’s recommendation. This also makes them a bit expensive. UV-A has not shown as wide a level of acceptance. You see these added to products and the disconnect seems to be in what can be proven in a lab and what can be proven in a real world setting.
This is another emerging technology that has some things that sound good, but also some red flags. Ionizers output charged ions that seek out viruses and contaminates and attach themselves to them. By doing so, they increase the weight, causing it to drop to the floor quicker (think about the 6 foot social distance recommendation). They also increase the size of the virus, making it easier to capture in an air filter. Now you might only need a MERV8 instead of a HEPA. Everything sounds good so far but here is the catch. To produce the ions many (not all) will also produce ozone, which is bad. Another issue is that ions only trap viruses; they do not kill them so you need a filtration device to remove the trapped particles. When looking at portable ionizers it is debatable if they can produce enough ions to be effective for the space.
Conclusion
Indoor Air Quality experts seem to agree that proper ventilation, fresh air and filtration are very effective in removing contaminates from the air we are breathing. They also agree that any one of these used individually is not a magic solution, so using a combination of these solutions is most effective. Past air movement and filtration it gets a little less clear. Technologies like UV and Ionizers may work, but further studies and real world testing needs to be done before there is a universal stamp of approval. If you do utilize UV or Ionizers, make sure you do your homework to ensure they are providing what they say they are and they are doing it in a safe way that does not have bad side effects.
To learn more about Air King’s fresh air solutions visit www.airkinglimited.com/fresh-air
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