Can an air purifier help protect you against the coronavirus?

I checked in with two of the top experts on indoor air quality: Joseph Allen, director of the Healthy Buildings program at the Harvard T.H. Chan School of Public Health, and Richard Corsi, dean of the Maseeh College of Engineering and Computer Science at Portland State University. In the fight against the coronavirus, both have championed the cause of placing portable air cleaners equipped with HEPA filters in school classrooms.

Here’s why: When infected people talk, sing, cough or even breathe, they release the virus into the air in a range of particle sizes. Although the large respiratory droplets fall quickly, the smaller aerosols can remain in the air for 30 minutes or longer until removed through ventilation or captured by an air-purification system. ...

If you have been staying at home with the same family members and don’t intend to change that, you probably don’t need one. But if someone in your household is an essential worker with a greater chance for exposure or your school-age children are back to in-person learning, you might consider investing in a purifier unit....

The two experts are not advising that you rely on purifiers to entertain company. “Having people into your home for a meal or perhaps staying several days is a big concern as the holidays approach,” Corsi says. “Some may have been exposed; others don’t even know that they are infected.” They emphasize that people should not cease wearing a mask or washing their hands just because they have a purifier. “Don’t let your guard down. A purifier may lower the level of particles in the air, but it doesn’t eliminate the risk,” Corsi says. ...