Skip to main content
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

  • Sam Houston State University Completes Athletic Stadium Renovations

    Sam Houston State University in Huntsville, Texas, recently announced the reopening of Elliott T. Bowers Stadium after an extensive renovation project, according to a news release. The university partnered with Stantec and DLR Group for the project’s design.

  • 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.

  • Planning with Clarity: Using AI to Make Better Campus Decisions, Not Just Better Designs

    Higher education leaders are being asked to make increasingly high-stakes decisions about campus facilities amid greater uncertainty than ever before. Social and economic pressures, shifting enrollment, and evolving learning models compete with growing deferred maintenance needs to strain even the most robust infrastructure budgets.

  • Can AI Help Build Stronger Communities in Student Housing?

    Student housing success is shifting from operational performance to student experience, with belonging now at the center. A recent 2025 report underscores a growing emphasis on student well-being, community, and engagement, signaling that expectations now extend beyond logistics to ensure students feel supported in their living environments. AI is enabling that shift by reducing administrative workload and giving teams more time to focus on meaningful student engagement.