UBC Okanagan researchers are exploring a new way to create personalized ventilation systems that would remove airborne pathogens to help reduce the spread of respiratory diseases in enclosed spaces.
With winter approaching and people spending more time indoors, the quality of the air they breathe becomes increasingly important. Especially during cold and flu season.
Researchers at UBC Okanagan are exploring an air-cleaning device that can remove airborne pathogens, offering a powerful new tool for reducing the spread of respiratory diseases in enclosed spaces.
The traditional approach to alleviating transmission of infectious diseases involves improving a building's ventilation system to regulate large-scale airflow, explains study co-author Dr. Sunny Li, professor in the School of Engineering .
Personalized ventilation systems go a step further by directing clean air towards a person from a fixed distance-similar to the air circulation system on passenger airplanes. But these systems have drawbacks, he says. A person needs to stay in the same position, or all people in the surrounding area need to be using the same system at the same time. There is also the discomfort of dry skin and eyes due to the constant exposure to the air.
"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 per cent of their time inside, making indoor air quality a critical factor for health and wellbeing."
Postdoctoral researcher Dr. Mojtaba Zabihi, the study's first author, explains that room layouts and ventilation systems vary significantly, making it challenging to implement changes in existing heating, ventilation and air conditioning systems. This highlights the importance of personalized ventilation.
"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.
The team of mechanical engineers, who work with UBC's Airborne Disease Transmission Research Cluster , created an induction-removal or jet-sink airflow concept to capture and remove exhaled aerosols before they can circulate through the room.
Unlike conventional personalized ventilation systems, which rely on high-speed air jets that can cause discomfort and lose effectiveness when users move, the new design redirects airflow around the person while continuously drawing contaminated particles into a localized purification zone.
"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."
Using computer simulations to model breathing, body heat and airflow during a 30-minute consultation scenario, the researchers compared their device against standard personal ventilation systems.
The results, published recently in Building and Environment , were dramatic. The new system reduced the probability of infection to just 9.5 per cent, compared with 47.6 per cent for a personal setup, 38 per cent for a personal ventilation system with an exhaust design, and 91 per cent under standard room ventilation.
Under optimal placement, the device prevented pathogen inhalation for the first 15 minutes of exposure, allowing only 10 particles out of 540,000 to reach another person. In fact, their simulations indicated it was able to remove up to 94 per cent of airborne pathogens.
"Traditional personalized ventilation systems can't adapt when people move or interact," explains Dr. Joshua Brinkerhoff, study co-author. "It's a smart, responsive solution for spaces like clinics, classrooms or offices where close contact is unavoidable."
Dr. Brinkerhoff says the study highlights the potential for airflow engineering-not just filtration-to improve indoor air quality and occupant safety. Future research will focus on refining the design for larger rooms and testing physical prototypes in clinical and public settings.
As a member of Canada's National Model Codes Committee on Indoor Environment, Dr. Zabihi hopes their research will help shape future ventilation standards, making indoor spaces safer and healthier for everyone.
UBCO researchers Drs. Sunny Li, Mojtaba Zabihi and Joshua Brinkerhoff are working on an indoor ventilation system to make the shared space cleaner and prevent the spread of pathogens.
