Using ‘active opening’ of windows for fire safety of modern buildings considering more realistic setup

Abstract

The ‘active opening’ of windows at the early stage of compartment fires has been proposed as an alternative fire safety measure to mitigate rapid fire spread and associated hazards. Following the conceptual exploration, recent scaled experiments using discrete wood crib fuels have demonstrated excellent mitigation effects. To comprehensively evaluate the practical performance of this strategy, a series of fire simulations were conducted to systematically examine the effects of key parameters, including variations in fuel distribution, ignition locations, window-opening modes, and detector arrangements. Results demonstrate that early ‘active opening’ substantially reduces smoke accumulation and thermal radiation feedback, effectively suppressing flame spread at moderate fire load densities (400 MJ/m2 and 400 MJ/m2). Even under severe conditions (800 MJ/m2), the strategy significantly delays fire growth and lowers façade heat flux, thereby reducing the likelihood of external fire spread. Comparative analysis further reveals that the ‘active opening’ strategy maintains consistent effectiveness across different window types that are easily adapted to modern buildings. Importantly, the findings reveal that optimal fire mitigation outcomes do not necessarily require simultaneous opening of all available windows. Instead, a ‘smart tiered opening’ strategy responsive to real-time fire development dynamics is recommended. The present research underscores the potential of integrating ‘active opening’ strategy into contemporary building design, requiring minimal modifications while delivering substantial improvements in mitigating fire and smoke risks.