Chennai: While there has always been wide speculation regarding the risk of Covid-19 transmission inside four-wheelers, scientists have now analysed airflow patterns inside the same.
Using computer simulations, they have attempted to shed light on the potential ways to reduce the risk of infection while sharing rides with others.
The study, published in the journal Science Advances, assessed the airflow inside a compact car with various combinations of windows open or closed.
The simulations showed that opening windows created airflow patterns that dramatically reduced the concentration of airborne aerosol particles exchanged between a driver and a single passenger,
The researchers, including those from Brown University in the US, said blasting the car’s ventilation system didn’t circulate air nearly as well as a few open windows.
“Driving around with the windows up and the air conditioning or heat on is definitely the worst scenario, according to our computer simulations”, said Asimanshu Das, co-lead author of the research from Brown university.
“The best scenario we found was having all four windows open, but even having one or two open was far better than having them all closed”. Das said.
In the research, the computer models simulated a car, loosely based on a Toyota Prius, with two people inside — a driver, and a passenger sitting in the back seat on the opposite side from the driver.
The scientists said they chose this seating arrangement since it maximised the physical distance between the two people.
Part of the reason opening windows is better in terms of aerosol transmission is because it increases the number of air changes per hour (ACH) inside the car that reduces the overall concentration of aerosols, the study noted.
According to the research, the driver was at slightly higher risk than the passenger since the average airflow in the car goes from back to front, but added that both occupants experience a dramatically lower transfer of particles.
The scientists said opening the windows next to each occupant carried a higher exposure risk, compared to putting down the window opposite each occupant.
“When the windows opposite the occupants are open, you get a flow that enters the car behind the driver, sweeps across the cabin behind the passenger and then goes out the passenger-side front window,” said Kenny Breuer, a professor of engineering at Brown University and a senior author of the research.