Add as a preferred source on Google

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

  • By Dian Schaffhauser
  • 03/08/21

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

  • California K–12 District Opens New Athletic Complex, Gym

    The San Mateo Union High School District (SMUHSD) in San Mateo, Calif., recently announced the completion of two new athletics facilities: a new gymnasium at Burlingame High School, and a new athletic training complex at San Mateo High School, according to a news release.

  • UNT Dallas Holds Ribbon-Cutting Ceremony for $100M STEM Building

    The University of North Texas at Dallas in Dallas, Texas, recently celebrated the opening of its new, $100-million STEM Building, according to local news. The ceremony on Dec. 2 preceded the first day of classes in the facility on Jan. 12, 2026.

  • Image credit: O

    Strategic Campus Assessment: Moving Beyond Reactive Maintenance in Educational Facilities

    While campuses may appear stable on the surface, building systems naturally evolve over time, and proactive assessment can identify developing issues before they become expensive emergencies. The question isn't whether aging educational facilities need attention. It's how institutions can transition from costly reactive maintenance to strategic asset management in a way that protects both budgets and communities.

  • Beyond Four Walls

    Operable glass walls provide a dynamic solution for educational spaces. They align with today’s evolving teaching methods and adapt to the needs of modern learners. Beyond the functional versatility, movable glass walls offer clean, contemporary aesthetics, slim and unobtrusive profiles, and versatile configurations that cater to the evolving needs of students and educators alike.

Digital Edition