Influences of vent location on the removal of gaseous contaminants and indoor thermal environment

Abstract

Heat sources and gaseous contaminants widely exist in modern buildings. Buoyancy-driven exchange flow through a large opening, such as a window, a doorway or an atrium, is ubiquitous in our daily life. Analogous experiments were carried out in a water tank to investigate the effect of vent location on the characteristics of the exchange flow. The model tank filled with coloured brine solution was immersed in a large reservoir filled with fresh water. The transient distribution of the reduced gravity is measured using a light attenuation technique. For the exchange flow through a vertical opening, the reduced gravity in the chamber is vertically stratified instead of uniformly distributed. Moreover, the density distribution was influenced by the location of the opening. The buoyancy-driven flow through a horizontal opening is highly oscillatory and the resulting density distribution is relatively uniform. Different models were proposed to estimate the ventilation flow rate through a vertical opening or a horizontal one. Hopefully, this study could provide useful advice with regards to the ventilation design and contaminant removal in buildings.