Ventilation systems could expose people to Covid-19: Study

A new study claimed that ventilation systems in modern buildings and offices that are designed to keep control the indoor air quality and temperature, especially during winters, can increase the risk of exposure to the coronavirus, as per the study published in the Journal of Fluid Mechanics.

A team of researchers from the University of Cambridge stated that highly popular mixing-ventilation systems that keep air condition uniform in all parts of the roomcan also disperse air contaminants throughout the room. These contaminants can carry the coronavirus as well.

Wearing masks mandatory

The researchers suggested this can be averted by wearing masks at all times so as to not contribute to the contaminants in the air.

Earlier studies also suggested that the coronavirus spread more quickly in enclosed spaces.

Lead author Professor Paul Linden from Cambridge’s Department of Applied Mathematics and Theoretical Physics (DAMTP), said in a statement: “As winter approaches in the northern hemisphere and people start spending more time inside, understanding the role of ventilation is critical to estimating the risk of contracting the virus and helping slow its spread.”

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He explained: “While direct monitoring of droplets and aerosols in indoor spaces is difficult, we exhale carbon dioxide that can easily be measured and used as an indicator of the risk of infection.”

“Small respiratory aerosols containing the virus are transported along with the carbon dioxide produced by breathing and are carried around a room by ventilation flows. Insufficient ventilation can lead to high carbon dioxide concentration, which in turn could increase the risk of exposure to the virus,” he further added.

The team stated in their study that the flow of large and aerosol particles depends on the placement of vents, windows, and doors. This also depends on other variables, including doors opening or closing, or changes in outdoor conditions for naturally ventilated buildings.

Movement of warm and cold air

Another factor that drives the flow of the contaminants is the movement of warm and cold air. Warm air, including exhaled breath, is collected in the upper zone. Hence, if ventilators are placed in the upper zone, it can extract the contaminants before someone could breathe them in.

The study suggests that when designed properly, displacement ventilation could reduce the risk of mixing and cross-contamination of breath. Hence, it can mitigate the risk of exposure.

The researchers also noted that masks are effective at reducing the spread of exhaled breath, and therefore droplets.

The team is now working with the Department for Transport looking at the impacts of ventilation on aerosol transport in trains and with the Department for Education to examine risks in schools this coming winter.