Air curtain in informal shopping malls: Optimization of the air curtain operating parameters for heat and smoke confinement

[Display omitted] •Optimization of air curtain operating parameters are examined in case of informal shopping mall fires.•About 6% to 38% improvement in sealing effectiveness by optimized air curtains (OAC) over vertical air curtains (VAC).•The optimized air curtain parameters depend strongly on the fire source-side fuel load.•A two-stage OAC barrier provides about 84% sealing effectiveness for heat and smoke confinement.•Special considerations to prevent side-leakage from inclined air curtain jet are examined and proposed. The operating parameters of commercially available air curtains, due to their promise in the confinement of fire-generated heat and smoke, have been systematically examined. Operating parameters such as the jet velocity, jet inclination angle, jet width, flow rate, and the number of air curtain jets are explored for the maximum possible sealing effectiveness in case of a fire event in informal shopping malls. Fire scenarios for nine different fire-source locations having two types of fuel loading in three informal shopping mall designs are numerically analyzed in this study. Against the extremely dense fuel load typically seen in informal shopping malls of different regions, the optimization of operating parameters of the air curtains yields about a 6% to 38% increase in sealing effectiveness in comparison with a commercial air curtain. The optimized air curtains in pairs, at the fire-origin and at the staircase, could confine up to 84% of the oncoming heat and provide crucial improvement in safe evacuation time. The findings of the present study provide a comprehensive understanding of the optimum configuration of the commercially available air curtains for improved effectiveness in heat and smoke confinement in such fire events.