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

  • URI Cuts Underwater Ribbon on New Ocean Robotics Laboratory

    The University of Rhode Island recently held a ribbon-cutting ceremony for a new Ocean Robotics Laboratory at its Narragansett Bay Campus, according to a news release. Two students used a remotely operated vehicle to cut an underwater ribbon in a 30-by-20-foot test tank.

  • Missouri Child Development Center Completes $2.3M Expansion

    The Urban Sprouts Child Development Center in St. Louis, Mo., recently announced the completion of a $2.3-million expansion and adaptive reuse project, according to a news release. The new space includes a retail café, outdoor learning space, and a support office building.

  • Houston-Area High School Receives Best Project Award from ENR

    Tomball West High School near Houston, Texas, recently received a K–12 Education Best Project Award in Engineering News-Record’s 2026 Texas & Southeast Best Projects Awards, according to a press release. The new facility was completed in May and opened its doors to students for the fall 2026 semester.

  • St. Lucie County, Fla., Breaks Ground on New K–8 School

    St. Lucie Public Schools in St. Lucie County, Fla., recently held a groundbreaking ceremony for a new K–8 school, according to a news release. The district partnered with Spiezle Architectural Group, Inc., for the design of the upcoming Ft. Pierce K–8 School, which comprises six buildings covering 215,000 square feet.