Assessment of People's Perception of Fire Growth: A Virtual Reality Study

One important aspect that is considered when designing safer buildings is human behavior. A comprehensive assessment of how people react during a fire, provides engineers valuable information, which will allow them to develop effective solutions to help people reach a safe place under tenable conditions. When evacuating a building, a key factor is pre-evacuation time, this is the lapse of time that starts when the person is alerted of a fire cue and ends once they evaluate the situation, before reacting and starting the purposive movement towards a safe place. Pre-evacuation times are associated with fire risk perception. The purpose of this thesis is to evaluate how people perceive fire growth risk in a fire scenario represented in virtual reality when compared to other methods, such as educational videos. The experiments included fifty-five test participants who were immersed in a virtual environment, where they had to predict the evolution of a fire and estimate if they could extinguish it with the help of a portable fire extinguisher. The results obtained showed that 97% of participants could not accurately estimate fire growth. Only 3% of people estimated a time difference that corresponded to the real time difference. In addition, there was a significant variation on the results (under/overestimation). A slightly higher number of responses underestimated the fire growth, this was observed in 56 out of the 104 incorrect responses. Finally, it was possible to derive that at later stages of fires people will not try to use a portable fire extinguisher.There are different behaviors that people may have when they are facing a fire emergency. One important aspect that is considered when designing safer buildings is human behavior. A comprehensive assessment of how people react during a fire, provides engineers valuable information, which will allow them to develop effective solutions to help people reach a safe place under safe conditions. When evacuating a building, a key factor is pre-evacuation time, this is the lapse of time that starts when the person is alerted of a fire cue and ends once they evaluate the situation, before reacting and starting the purposive movement towards a safe place. Pre-evacuation times are associated with fire risk perception. The purpose of this thesis is to evaluate how people perceive fire growth risk in a fire scenario represented in virtual reality when compared to other methods, such as educational videos. This was accomplished by reviewing literature available of the previous experiment, “People’s Subjective Estimation of Fire Growth: An Experimental Study of Young Adults” by (Fridolf and Nilsson, 2011). In the second part of the project experiments were carried out using a head mounted display to recreate the virtual environment. In the last part of the project the data was selected and analyzed. The results obtained were compared between different the two different methods (Virtual Reality vs. Educational videos). The experiments included fifty-five test participants who were immersed in a virtual environment, each participant had to estimate two different fire growths. The results of this study can be used to argue that young adults (who represented the majority of the population) are not very good at predicting fire growth at various stages of the fire, which may explain why in real case scenarios some time elapses when people received the first cue, before starting to evacuate towards the emergency exits. The results obtained showed that 97% of participants could not accurately estimate fire growth. Only 3% of people estimated a time difference that corresponded to the real time difference. A slightly higher number of responses underestimated the fire growth, this was observed in 56 out of the 104 incorrect responses. Nevertheless, no significantly difference was found on the results to conclude that people tend to under/overestimate the fire growth, only a small percentage of the population which took part of the experiments estimated a time difference that corresponded to the real time difference. The second part of the experiment consisted of participants observing a fire and they were required to answer if they thought it was possible to extinguish the fire with a portable fire extinguisher, it was possible to derive that at later stages of fires people will not try to use a portable fire extinguisher. This study suggest that virtual reality can be used as a research tool as an alternative method to study human behavior in fires, but high level of realism in the VR scenarios is required in order to use it for the evaluation of risk perception. Future validation studies will help increasing the understanding on its effectiveness in these types of scenarios. Accomplishing higher levels of realism could contribute to achieve behaviors similar than the ones people have on real case scenarios. Further studies should be done with larger number of participants and different scenarios is recommended adding extra cues to the virtual environment such as sound and a greater level of detail should be achieved on the different modelled objects to accomplish a higher immersion on the scenarios