Effects of Perforation Pattern on the COVID-19 Exposure Time at Office Rooms Using Perforated Duct Diffusers

Ventilation systems have a high impact on air quality and thermal comfort. So, it is vital to improving the ventilation efficiency to parallelly reach a more uniform age of air (AoA) distribution and to decrease the total energy usage (less required outdoor airflow). In this paper, a validated numerical model has been used to investigate the effects of the perforation pattern and direction of air diffusers on the COVID-19 exposure time. Four types of perforated duct diffusers (PDD) were simulated using a k-ε Realizable turbulence model at the heating mode. Given the ASHRAE standards procedures and local AoA investigations, it is shown that vertical perforations would be more effective than the other types in terms of lowering exposure time. Besides, the results prove PDDs create a unidirectional pattern indicating their high preventing performances, in general.