Fire Safety Design Process for Exterior Wall Openings From the Perspective of Compartment Fire Growth and Ejected Flames

This study proposes a fire safety design process for sequentially assessing fire spread through exterior wall openings following compartment fire development. The growth rate of fire and time to flashover are evaluated based on the fire load density, and the potential onset of external flaming is determined by considering both flashover and window function loss. The horizontal fire spread is assessed using the radiative heat flux to estimate the required separation distance, whereas the vertical thermal exposure is evaluated using the centerline temperature of the ejected fire plume. The proposed process was demonstrated using an application scenario based on the geometric conditions of the Grenfell Tower fire compartment and was further examined using existing full-scale compartment fire experimental data. The results revealed that the potential onset and thermal influence range of fire spread through exterior wall openings could be evaluated using a continuous engineering procedure. Therefore, the proposed method is applicable in design-stage fire risk assessment, rather than in the detailed prediction of actual fire behavior.