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

  • Secret to Efficient, On-Time School Infrastructure & Modernization Projects is All in the Preparation

    Warmer weather and longer days make summer the ideal time for construction and modernization projects at educational facilities. School boards and construction firms must coordinate effectively to ensure that these projects do not extend even a single day into the school year and impede classroom operation.

  • Building Beyond Simulation: Creating Immersive Ecosystems for Healthcare Education

    Health sciences education is one of the fastest-growing facility types in colleges and universities. The demand for medical, nursing, and allied health professionals is driving the creation and renovation of medical simulation training facilities that provide students with real-world experience through advanced simulation-based learning.

  • Spaces4Learning Announces 2026 Product Award Winners

    Spaces4Learning has just announced the winners of the 2026 Product Awards! The award program spotlights outstanding product development achievements of manufacturers and suppliers whose products or services are considered to be particularly noteworthy in their ability to enhance K–12 and higher-education learning environments.

  • 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.