Pathfinder
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Research Brief: New study explores how coronavirus travels indoors
July 28, 2020
A numerical simulation shows aerosol transport and deposition in a small classroom setting with an asymptomatic instructor and the ceiling ventilation system located in the back (top) and front (bottom) of the classroom.
Credit: Suo Yang, University of Minnesota
...
The researchers found that in indoor spaces, good ventilation will filter some of the virus out of the air, but may leave more viral particles on surfaces. In the classroom setting, after running a 50-minute simulation with an asymptomatic teacher consistently talking, the researchers found that only 10 percent of the aerosols were filtered out. The majority of the particles were instead deposited on the walls.
“Because this is very strong ventilation, we thought it would ventilate out a lot of aerosols. But, 10 percent is really a small number,” said Yang, who holds the Richard and Barbara Nelson Assistant Professorship in Mechanical Engineering. “The ventilation forms several circulation zones called vortexes, and the aerosols keep rotating in this vortex. When they collide with the wall, they attach to the wall. But, because they are basically trapped in this vortex, and it’s very hard for them to reach the vent and actually go out.”
In each scenario, the researchers mapped the air flow to find locations of virus “hot” spots, or where the aerosols congregated. With the right combination of ventilation and interior organization, it could be possible to mitigate the disease spread and avoid these hot zones, the researchers said.
For example, in a classroom setting, the virus aerosols spread significantly less throughout the room when the teacher—who is likely doing the most talking—was placed directly under an air vent. This insight could inform how classrooms are arranged and disinfected, and also help places like theaters and concert venues reopen with the proper precautions.
...
Read the full paper entitled “Risk assessment of airborne transmission of COVID-19 by asymptomatic individuals under different practical settings” on the ArXiv website.
https://twin-cities.umn.edu/news-eve...ravels-indoors
July 28, 2020
A numerical simulation shows aerosol transport and deposition in a small classroom setting with an asymptomatic instructor and the ceiling ventilation system located in the back (top) and front (bottom) of the classroom.
Credit: Suo Yang, University of Minnesota
...
The researchers found that in indoor spaces, good ventilation will filter some of the virus out of the air, but may leave more viral particles on surfaces. In the classroom setting, after running a 50-minute simulation with an asymptomatic teacher consistently talking, the researchers found that only 10 percent of the aerosols were filtered out. The majority of the particles were instead deposited on the walls.
“Because this is very strong ventilation, we thought it would ventilate out a lot of aerosols. But, 10 percent is really a small number,” said Yang, who holds the Richard and Barbara Nelson Assistant Professorship in Mechanical Engineering. “The ventilation forms several circulation zones called vortexes, and the aerosols keep rotating in this vortex. When they collide with the wall, they attach to the wall. But, because they are basically trapped in this vortex, and it’s very hard for them to reach the vent and actually go out.”
In each scenario, the researchers mapped the air flow to find locations of virus “hot” spots, or where the aerosols congregated. With the right combination of ventilation and interior organization, it could be possible to mitigate the disease spread and avoid these hot zones, the researchers said.
For example, in a classroom setting, the virus aerosols spread significantly less throughout the room when the teacher—who is likely doing the most talking—was placed directly under an air vent. This insight could inform how classrooms are arranged and disinfected, and also help places like theaters and concert venues reopen with the proper precautions.
...
Read the full paper entitled “Risk assessment of airborne transmission of COVID-19 by asymptomatic individuals under different practical settings” on the ArXiv website.
https://twin-cities.umn.edu/news-eve...ravels-indoors