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

  • College of the Desert Hits Construction Milestone on New Campus

    College of the Desert recently announced that the construction of its new Palm Springs Campus in Palm Springs, Calif., recently reached a major construction milestone, according to a news release. The college is partnering with general contractor C.W. Driver Companies, which recently “topped out” the facility by placing the final beam in its structure.

  • Zurn Elkay Releases 2025 Sustainability Report

    Zurn Elkay Water Solutions recently announced the release of its annual sustainability report, according to a news release. The 2025 report discusses the organization’s efforts to maintain good environmental stewardship and the solutions provided in helping customers meet sustainability goals.

  • Health & Science Building

    Health & Science Building

    Established in 1999, the Education Design Showcase is a vehicle for showing off innovative — yet practical — solutions in planning, design, architecture, and construction. The College of Western Idaho's Health & Science Building has been recognized with an EDS 2026 Project of Distinction award in the category of New Construction.

  • Vanderbilt to Partner with ABM for Campus Preservation and Modernization

    Vanderbilt University recently announced that it has selected ABM Performance Solutions for a preservation and modernization project at its New York City campus, according to a news release. ABM will deliver its end-to-end ABM Performance Solutions (APS) model to manage critical operations during renovation and maintenance.