New air purifiers filter at least 90% of COVID-carrying particles, researchers say

An army of do-it-yourselfers is trying to clear the air of COVID-19. One group at the University of California, San Diego, is building 250 homemade air purifiers for classrooms and labs around campus, and they say their box-style purifier filters at least 90% of the particles that carry the virus. 

The Corsi-Rosenthal boxes, named for the two men who created the purifiers, are made up of four air filters on the sides. As air flows in, an electric fan on top draws out the purified air.

"The virus, if it's there, will get trapped in the filter material," said Kim Prather, professor at the Scripps Institution of Oceanography at UC San Diego. 

She studies microscopic particles called aerosols and has been a key voice in spreading the message that good ventilation and filtration are important in the fight against COVID-19.

Research shows an infected person can spread the virus through aerosols that float through a room and, like cigarette smoke, build up over time in poorly ventilated spaces.

"It's a very fixable problem," Prather said. "Once you acknowledge it's in the air, you can remove it using really simple methods like this." 

"We think of it as a Swiss cheese sandwich, where with Swiss cheese, it has holes in it, and no layer of protection will keep you totally safe, but by layering these multiple levels of protection together is going to be able to keep the campus more safe during the COVID-19 pandemic as these go into a mixture of lecture halls and instructional labs," UC San Diego dean of the division of biological sciences Kit Pogliano told CBS San Diego affiliate KFMB-TV.

The university's student body president told the outlet it takes just 15 minutes to assemble one of the boxes.

"The tape makes a good seal and once the seal is complete, you put on the fan and tape up the fan, and add a little shroud," Manu Agni said.

The Corsi-Rosenthal boxes are taking off — from Hawaii, where 9-year-old Kahlen gives easy to follow instructions, to Canada, where the boxes are artfully decorated. They cost under a hundred dollars each.

Jim Rosenthal, who helped design the box, owns a company that makes air filters. 

"Are you getting, forgive me, fan mail?" CBS News chief medical correspondent Dr. Jon LaPook asked.

"My fan mail is basically all the people who have adopted this project as their own," Rosenthal said.

In:
• COVID-19