Abstract The work presented in this paper illustrates the concept of numerical simulations for real-time 'Numerical Fire Forecast' (NFF), applied to smoke control management in large spaces. The numerical calculations performed within the Inverse Zone Modelling framework are based on a series of full scale experiments conducted using the Japanese Building Research Institute (BRI) fire test facility. The experimental set-up consists of a large space of 720m 2 floor area and 26.3m ceiling height, equipped with shafts and fans to study different smoke control options. The measurements include the smoke layer interface (from thermocouples, photometers and visual observation), the smoke layer temperature at different heights (using thermocouples) and the mass flows of air and hot smoke through mechanical and natural vents. In the case of natural filling (i.e. no mechanical or natural venting), the assimilation of smoke layer height data within a 30 s window results in more than 4 minutes lead time of the forecast, with a good level of confidence. Predictions are given in terms of smoke layer height and upper layer temperature. The steady-state value of the methanol fire (Q c = 1300 kW) has been estimated after 30 s with less than 10% error. Widening the assimilation window does not improve the forecast. When mechanical ventilation is activated after the assimilation process with a sufficiently high exhaust rate, the forecast shows with a relatively substantial positive lead time, safe levels of smoke interface height. Introduction Fire Safety Engineering is a multi-disciplinary science, which aims at designing fire-safe buildings with appropriate solutions to preserve property and, most importantly, human life. Therefore, before the construction (or the renovation) of a building, architects, fire engineers and regulators need to consider a given set of fire scenarios in order to examine different options and choose the most appropriate one(s). For this purpose, a large amount of tools have been developed across the years in order to provide an answer to various questions that arise when studying the complex phenomenon of a fire. These questions are often related to the integrity of the building (fire resistance of the structure), fire and smoke spread, and evacuation. The tools used range from simple engineering hand-calculations to the more sophisticated computational fluid and solid mechanics. Many fire simulation tools have been developed to provide guidance in a priori studies. The level of complexity already reached in these tools and the required computational resources render their use for real time predictions impossible. Subsequently, fire fighters have to rely on their intuition and experience as to the decisions and actions to take in real fire situations. It is in this context that the concept of sensor assisted fire fighting has emerge
