When used correctly, air purifiers can help reduce pollutants in the air, including viruses, in the home or in confined spaces. However, on its own, a portable air purifier is not enough to protect people from COVID-19.HEPA stands for “high-efficiency particulate air” and is a type of filter that can trap and remove microscopic particles, such as COVID-19 viruses, from the air. In that sense, a HEPA air filter can protect against COVID-19 from spreading to someone from an infected person. However, as noted by the EPA, it takes a multi-pronged approach to combating COVID and other viruses.
COVID-19 does not expel itself. It has to stick to something else to travel, such as mucus, a respiratory droplet, or a piece of dust in the environment. A HEPA filter doesn't kill the COVID-19 virus, but items that can carry the virus stick to the filter so they can't circulate in your living area. The optimal location for HEPA air purifiers will depend on the unique conditions of each room, but they are likely to be most effective when placed as close to occupants as possible.
We know from previous research that air filters with a sufficiently high degree of filtration can reduce the amount of viral contaminants in the air. Appliances that use HEPA filters only work when turned on, so you may need to run your oven fan continuously or for longer periods of time. These findings support the utility of portable HEPA air filters and universal masking to reduce exposure to indoor aerosols containing SARS-CoV-2.The team collected air samples from the rooms for one week when the air filters were on and 2 weeks when they were turned off, and then compared the results. A true HEPA filter can be used in purifiers throughout the house to make the air cleaner and less polluted.
Do-It-Yourself (DIY) air filters are indoor air filters that can be assembled from box fans and square HVAC (or oven) filters. Keep in mind that unless you have someone with an active COVID-19 infection in your household, you won't have any source of coronavirus to reduce or filter with any of these methods.The results of this study support the use of portable HEPA air purifiers to reduce exposure to airborne particulate matter. Ventilation systems can be supplemented with portable high-efficiency particulate air (HEPA) cleaners to reduce the amount of infectious airborne particles. Research at a hospital flooded by people with COVID-19 has confirmed that portable air filters effectively remove SARS-CoV-2 particles from the air, the first such evidence in a real environment.A true HEPA filter is not as powerful as a medical grade HEPA filter, but it meets the HEPA rating for removing at least 99.7% of 0.3 micron particles.
These findings suggest that portable HEPA air purifiers may reduce exposure to SARS-CoV-2 aerosols indoors, and that greater reductions in exposure occur when used in combination with universal masking.This type of HEPA filter has a grade of H13-H14, which indicates that the filter can remove 99.95% to 99.995% of particles that are only 0.1 microns in size. In this study, the use of HEPA air purifiers in a conference room significantly reduced the exposure of nearby participants and a speaker to airborne particles produced by a simulated infected participant. In conclusion, using a HEPA filter is an effective way to reduce exposure to airborne particulate matter and SARS-CoV-2 aerosols indoors. A true HEPA filter is capable of trapping and removing microscopic particles such as COVID-19 viruses from the air.
However, it should be noted that using an air purifier alone is not enough to protect people from COVID-19; it should be used in combination with other measures such as universal masking and proper ventilation.