Two air cleaning systems placed close to each other resulted in the best filtration, lowering the risk of viral transmission.
A recent study conducted by investigators from the American Institute of Physics has discovered that low cost box fans can improve ventilation and significantly reduce the risk of COVID-19 transmission.
Results from the study were published in the journal Physics of Fluids.
"Placing the air cleaner near the potential infector is the most effective way to reduce the aerosol spread," Jiarong Hong, an author on the study said. "At this location, owing to its proximity to both the infector and the HUV, the air cleaner extracts the majority of aerosols, leaving only a small percentage suspended in the air.”
For the study, the team of investigators used 2 air cleaning systems to measure the clean air delivery rate at two independent laboratories. The 2 systems were a box fan air cleaner and a system known as HUV.
To stimulate the airborne virus, they used tobacco smoke due to the fact the virus Is known to travel in the air after exhalation.
They then incorporated the measurements into a computer model of a classroom. The model simulated a cloud of virus particles released from an infected individual and experimented with different placements of the air cleaning systems.
Findings from the study showed that the best results were seen when the 2 air cleaning systems were closest to the infected individual. However, while it is not always known who is infected, the investigators recommended placing the box fan near the HUV system.
"In addition, we find that in large classrooms, distributing multiple air cleaners in the space is more effective in controlling aerosol spread than simply enhancing the flow rate of the HUV or air cleaners alone," Hong said.