Dispersion of exhaled droplet nuclei in a two-bed hospital ward with three different ventilation systems

Finding an effective ventilation system that can contribute to minimizing the airborne transmission of infectious diseases in hospital wards at relatively lower cost was the aim of that study. The authors investigated the penetration of exhalation jets from a lying person and the distribution of exhaled droplet nuclei in a ward with three different ventilation systems (mixing, downward and displacement ventilation). Two breathing thermal manikins were used to simulate a source patient and a receiving patient, and two different modes of exhalation from mouth and nose were studied.The results provide additional evidence that displacement ventilation is not applicable in hospital wards.