Classroom Purifier Cuts Infection Risks in Half—Same as Opening Windows

A study in two South Korean high schools found that window ventilation reduced the risk of COVID-19 infection by 55%, while the use of an air purifier shrank the risk by 50%. The combination of the two dropped the risk by nearly three-quarters (73%). Researchers from the Infrastructure Safety department at the Korea Institute of Civil Engineering and Building Technology (KICT) said the use of the air-purifying device worked best when it was placed in the middle of the room, which was sized to hold about 25 students.

The study ran several rounds in which the performance of various antiviral and antibacterial air purifiers was tested in an actual classroom. Virus-like salt microparticles were released into the air as aerosols, and the researchers measured the concentration levels in succession in the center and at the edge of the room during each round to simulate the presence of an infectious student.

For a final round, the researchers worked with a specific air purifier: the AiroDoctor WAD-M20. The testing, which ran over the course of several days, assumed that students didn't move about the space and maintained distances from each other.

The AiroDoctor is a $4,000, free-standing device about the size of a 13-gallon garbage can. According to coverage of the study, students weren't bothered by noise from the machine.

"We are very pleased about the groundbreaking results from South Korea," said Carsten Hermann, managing director of ScreenSource GmbH, which produces the machine, in a press release. "We trust that the relevant authorities nationally and internationally will take notice of such important studies. After all, the globally unique filter technology of the AiroDoctor can make an important contribution in a long-term strategy against SARS-CoV-2."

About the Author

Dian Schaffhauser is a former senior contributing editor for 1105 Media's education publications THE Journal, Campus Technology and Spaces4Learning.

Featured

  • Carnegie Mellon University Receives $3B Gift to Launch New Campus

    Carnegie Mellon University in Pittsburgh, Penn., recently announced that it has received $3 billion—the largest individual gift in higher education history—from Citadel CEO and founder Ken Griffin, according to a news release.

  • Longwood University Hits Construction Milestone on New Music Education Facility

    Longwood University in Farmville, Va., recently celebrated the topping out of its new music education and performance facility, according to a news release. The university partnered with development and construction firm Skanska on the 63,800-square-foot facility, which began construction in August 2025 and has an estimated completion date of fall 2028.

  • UPenn Announces Completion of New Veterinary Education Facility

    The University of Pennsylvania in Philadelphia, Penn., recently finished construction on an 11,800-square-foot veterinary education building, according to a news release. The Gail P. Riepe Center for Advanced Veterinary Education is the first dedicated classroom facility at the New Bolton Center, a large-animal hospital and campus about 35 miles west of the campus proper.