Jet fans are increasingly preferred over traditional ducted systems as a means of ventilating pollutants from large spaces such as underground car parks. The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) -which causes novel coronavirus disease (COVID-19)- through the jet fans in the underground car parks has been considered a matter of key concern. A quantitative understanding of the propagation of respiratory droplets/particles/aerosols containing the virus is important. However, to date, studies are yet to demonstrate the viral (e.g. SARS-CoV-2) transmission in the underground car parks equipped with jet fans. In this paper, the numerical simulation has been performed to assess the eﬀects of jet fans on the spreading of viruses inside the underground car parks.