Influence of different Personalized Air Terminal Devices on the motion of expiratory droplets released in the closed vicinity of the occupant

Abstract

Recent concerns about airborne disease spread (SARS, tuberculosis, influenza, est.) via expiratory droplets dispersion identified the necessity for the new air distribution system which will be able to provide protection to the occupants. Personalized Ventilation (PV) is one of the technologies that provide a possible solution. Three different air terminal devices (ATD) designs were examined using computational fluid dynamics (CFD) simulation in this study: Desktop with 2 ATDs (2-DT ATD), Desktop with single ATD (1-DT ATD) and circular perforated panel (CPP) ATD. Three PV flow rates were used: 5, 10 and 20 l/s together with ceiling mounted mixing ventilation (MV) supplying room with 3 ACH-1. The performance of these three ATDs to protect the occupant from cough droplets released 2m sideways from the occupant at the height of 1.7m (resembling standing person) is reported. The results from the study indicate that 1-DT ATD performed the best for all flow rates and the configuration with 2-DT ATD at the flow rate of 5 l/s achieved small improvement compared to MV.