Simple Airflow Shift Cuts Indoor Infection Risk by Up to 90%

A new airflow system could dramatically reduce the spread of airborne disease indoors.

During winter, when people spend more hours inside, the air they breathe indoors becomes a growing concern. This issue is especially important during cold and flu season, when respiratory illnesses spread more easily in enclosed spaces.

At the University of British Columbia, Okanagan, researchers are studying a new air-cleaning device designed to remove airborne pathogens. The technology could offer a powerful way to limit the spread of respiratory diseases in indoor environments.

Limits of Traditional Ventilation Systems

Study co-author Dr. Sunny Li, a professor in the School of Engineering, explains that the most common strategy for reducing disease transmission indoors focuses on improving a building’s ventilation system to control airflow throughout large spaces.

Some systems attempt to improve protection by directing clean air toward an individual from a fixed point, much like the air vents found on passenger airplanes. Dr. Li notes that this approach has clear drawbacks. Users often need to remain in one position, or everyone nearby must use the same setup at the same time. Continuous airflow can also cause discomfort, including dry skin and irritated eyes.

“Ensuring high air quality while indoors is crucial for mitigating the transmission of airborne disease, particularly in shared environments,” says Dr. Li. “Many Canadians spend nearly 90 percent of their time inside, making indoor air quality a critical factor for health and well-being.”

The Need for Personalized Indoor Air Solutions

Postdoctoral researcher Dr. Mojtaba Zabihi, the study’s first author, points out that indoor spaces differ widely in layout and ventilation design. Because of these differences, upgrading existing heating, ventilation and air conditioning systems can be difficult. This challenge underscores the value of personalized ventilation solutions.

“We wanted to develop an innovative system that prevents occupants from inhaling contaminated air while allowing them to use a personalized ventilation system comfortably for extended periods,” he says.

Working with UBC’s Airborne Disease Transmission Research Cluster, the mechanical engineering team developed an induction-removal or jet-sink airflow approach. The concept focuses on capturing exhaled aerosols before they have time to spread through a room.

How the Jet Sink Airflow Design Works

Conventional personalized ventilation systems often rely on fast-moving air streams. These can feel uncomfortable and tend to lose effectiveness when people shift positions. The new system takes a different approach by guiding airflow around the individual while continuously pulling contaminated particles into a small, localized purification area.

“Our design combines comfort with control,” says Dr. Zabihi. “It creates a targeted airflow that traps and removes exhaled aerosols almost immediately — before they have a chance to spread.”

To evaluate the system, researchers ran computer simulations that accounted for breathing patterns, body heat and airflow during a 30-minute consultation scenario. The new design was then compared with standard personal ventilation setups.

Dramatic Reductions in Infection Risk

The results, recently published in Building and Environment, showed a striking improvement. The new device reduced the risk of infection to 9.5%. In comparison, the risk reached 47.6 percent with a typical personal setup, 38 percent with a personal ventilation system using an exhaust design, and 91 percent under standard room ventilation.

When positioned correctly, the device blocked pathogen inhalation during the first 15 minutes of exposure. Only 10 particles out of 540,000 reached another person. Simulations also showed the system could remove up to 94 percent of airborne pathogens.

“Traditional personalized ventilation systems can’t adapt when people move or interact,” explains study co-author Dr. Joshua Brinkerhoff. “It’s a smart, responsive solution for spaces like clinics, classrooms, or offices where close contact is unavoidable.”

Shaping the Future of Indoor Air Safety

Dr. Brinkerhoff adds that the findings highlight how airflow engineering, not only filtration, can play a major role in improving indoor air quality and protecting occupants. The research team plans to refine the design for larger spaces and test physical prototypes in clinical and public settings.

As a member of Canada’s National Model Codes Committee on Indoor Environment, Dr. Zabihi hopes the work will contribute to future ventilation standards, helping make indoor environments safer and healthier for everyone.

Reference: “A novel aerosol induction-removal system for mitigating airborne disease transmission in shared indoor environments” by Mojtaba Zabihi, Ri Li and Joshua Brinkerhoff, 15 August 2025, Building and Environment.
DOI: 10.1016/j.buildenv.2025.113569

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