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

  • Designing Learning Spaces that Support Student Mental Health and Wellness

    In today’s education landscape, schools are more than just centers for learning; they are integral to the holistic development and well-being of students. The global pandemic underscored the importance of addressing mental health in schools, as productivity dropped, stress levels rose and students faced challenges managing emotions.

  • Spaces4Learning Announces Winners of 2025 Product Awards

    Spaces4Learning has just announced the winners of the 2025 Product Awards! The award program recognizes innovation and excellence in products that enhance learning environments in K–12 schools and institutions of higher education.

  • Kraus-Anderson Completes Improvements at Minnesota Middle, High Schools

    Construction management, real estate, and risk management firm Kraus-Anderson recently announced that it has finished two K–12 renovation projects in Minnesota, according to a news release.

  • Empowering People Through Smart, Sustainable Campuses

    Sustainability is facing increasing scrutiny, with some questioning its costs and priorities. Yet for universities, it remains an essential driver of resilience, operational efficiency and long-term competitiveness. At the same time, there is a growing recognition that sustainable transformation is not just about reducing energy consumption and emissions to comply with tightening regulations ‒ it’s about creating vibrant, comfortable environments where people can thrive, innovate and connect. For university leadership, this is a complex balancing act, with rising energy costs and limited budgets only adding to the challenge.