Assessing Ventilation Strategies to Reduce the Spread of Pathogens in Restaurants

Abstract

Since first recognizing COVID-19 as a rapidly spreading virus, research has been pursued to determine how to reduce or mitigate the transmission. Many restaurants reduced capacity and increased distance between tables to maintain social distancing. However, patrons remove masks while eating and this does not guarantee the prevention of viral transmission. The goal of this study was to understand how virus spreads in an air-conditioned restaurant using computational fluid dynamics. Three configurations for supply and return vents were modeled in a scenario where a carrier sneezes and releases virus-laden saliva droplets into the air. The distributions of droplets airborne, deposited on surfaces and exhausted through return vents, were compared to determine where vent configuration reduces the risk of infection for patrons. The effect of air changes per hour (ACH) was studied by comparing the percentages of airborne and exhausted droplets. Lastly, two vent configurations were compared in a scenario with multiple diners talking within the span of 2 minutes. A staggered supply vent configuration was found to be most effective in removing airborne particles. Increasing ACH decreased the percentage of airborne particles. Smaller respiratory particles released by activities like talking have a higher percentage being exhausted than larger sneeze droplets.