If you are wondering whether or not air purifiers can halt the spread of the coronavirus, you have come to the right place.
The short answer to that is that HEPA filters are capable of capturing particles smaller than coronavirus. However, health authorities have made no statement about the efficacy of these devices in arresting the proliferation of the coronavirus.
Simple common sense also indicates that air purifiers and HEPA filters may not work in some cases. For instance, if you are sitting close to an infected person, then you will breathe in the coronavirus-vapors before they reach the filter.
Also See: Best Air Purifier for Viruses
Back in April 2020, researchers expressed concern that air is a possible route for coronavirus transmission. Since then, several experts have written to the WHO stating that coronavirus is airborne. After that, the WHO acknowledged that the coronavirus pandemic can possibly spread by air.
Coming back to air purifiers and HEPA filters. The coronavirus has a diameter of about 0.125 micron, which is substantially larger than the 0.01 micron diameter particles that HEPA filters can capture effectively.
There were some erroneous reports in the media that HEPA filters cannot capture particles under 0.3 microns and are therefore incapable of capturing coronavirus. However, HEPA filters may have the capability of capturing much smaller particles than this.
One NASA study shows that HEPA filters can capture almost 100% of 0.01 micron particles. Thus, HEPA filters may be efficient at capturing particles under 0.3 microns.
This does not necessarily mean that installing an air purifier can fully protect you. Currently, the official position of the CDC is that the coronavirus can spread mainly through virus-laden droplets that come through sneezing and coughing and through person-to-person contact.
However, in reality, the coronavirus is spreading even care has been exercised in this regard. The problem is that the coronavirus is recent, so there is not a lot of reliable scientific evidence about how it spreads.
One important factor to consider in this regard is the concentration level of the coronavirus in the air that can lead to infection and also the time required. HEPA filters have an effective particle removal rate of 99.97% for particles that are 0.3 microns or bigger. As a result, this filter type is commonly used in hospital settings. There are no studies yet on whether or not HEPA filters can bring down coronavirus concentration levels and stop infections.
Besides HEPA filters, there are also electrostatic and ionizing purifiers. Air purifiers using this technology rely on other methods, besides a physical filter to remove particles from the air. The advantage of these devices is that they can save you the hassle of changing filters. However, the effectiveness of these non-filter purifiers varies with make and model. There is very little research on how effective these filtration methods are for stopping the spread of coronavirus.
Although you might want to consider air purifier filters to stop the spread of the coronavirus, there is another filter that you can make use of: face masks. Right now, it seems that the safest bet for stopping infections is to follow official guidelines on social distancing, isolation, face masks and hand washing.