Do Air Purifiers Help with Viruses in the Air?

When used correctly, air purifiers can be a great tool to reduce pollutants, including viruses, in the home or in confined spaces. However, they are not enough to protect people from COVID-19 on their own. To be effective, an air purifier must be able to constantly suck in enough air to reduce the amount of virus particles in the air. The speed at which an air cleaner can circulate air through the filter is measured by its Clean Air Supply Rate (CADR) number.

In a general room, researchers found SARS-CoV-2 particles in the air when the filter was turned off, but not when it was turned on. While air purifiers can trap virus particles that have been transmitted through the air, they cannot do anything about viruses on a person or on a hard surface. Air and HVAC filters are designed to filter contaminants from the air passing through them. However, an air purifier can only filter the air in the room it is placed in, so other parts of the house may remain untreated.

To be effective in removing viruses from the air, an air purifier must be capable of removing small particles in the range of 0.1-1um. In circumstances where you cannot open windows or doors for ventilation, closing the house and turning on the air purifier is a good option. Do not use air filters that intentionally generate ozone in occupied spaces or that do not comply with state regulations or industry standards for ozone generation. Using an air purifier at home can be beneficial at any time to help filter indoor allergens and contaminants, such as fumes from kitchen and cleaning products.

It is important to select a model that can accommodate the air volume of the room where you will place it. While most virus droplets fall to the ground quickly, some research suggests that smaller particles may stay in the air longer.