Experimental study of the transverse diffusion of pollutants through a downward plane jet in a room

Recently, a new type of ventilation method known as protected zone ventilation has been studied for application to the prevention of indoor contaminants transported from one zone to another. The use of a downward plane jet plays a key role in a protected zone ventilation system. The objective of this study is to examine the transmission of contaminants through a downward plane jet in a room with gaseous contaminants. Experimental measurements were carried out in a full-scale test room under isothermal conditions at Aalto University, Finland. The results showed that the measured concentration profiles may match the calculated profiles when the supplied air velocity is higher than 1.5 m/s, by which the downward plane jet may separate the room into two zones with different concentrations. The results of this study may be used to guide the design and optimisation of protected zone ventilation systems.