Researches of the pre-evacuation time of people in residential multi-storey buildings without fire warning systems

Introduction. According to statistics, the greatest loss of life from fires in Russia occurs in residential buildings with a height up to 28 m. At the same time, most fire protection systems are not provided in such type of buildings. In particular, in residential buildings of mentioned above height fire alarm system maybe not. That is why the real values of the pre-evacuation time (PET) in the buildings are not known, because domestic research still has not been conducted. Goals and objectives. The aim of the work was to establish the values of the PET of people in a residential building that is not equipped with a fire alarm system. The main tasks were to study the time to warn building occupants about a fire and to research the time of people's reaction to a fire warning. Methods. The method of scientific research in this work is a full-scale experiment. In the first set of experiments focus were on warning time — it was investigated how much time it took to warn all building occupants by 1, 2 and 3 notifiers. The second set of experiments were aimed to study of people's reaction time to a fire alarm — it was determined how long it took to start evacuating from their apartments. Results and their discussion. Studies have shown that the value of the alert time of a nine-storey building by one, two and three notifiers averaged was 20.0, 11.6 and 7.2 min, respectively. Based on the data obtained, a mathematical model was built that allows predicting the optimal number of notifiers depending on the number of storeys in the building. Studies of people's reaction time to a fire alarm have shown that during the daytime, on average, people need less time to realize and prepare for evacuation (72 s) than at night (112 s). Combining the results obtained allowed us to determine the optimal number of notifiers to warn all people in residential building. Conclusion. Comparison of the experimental values of the PET with the data of the current Methodology of fire risk calculation for a nine-storey house showed a discrepancy of 2.6 times.