This paper reports on the authors’ research methodology and outcomes from 21 test scenarios of fires in colonial and ranch-style structures at UL’S Large Fire Laboratory in Northbrook, Illinois, with different ventilation conditions; all fires were started from a small flaming source and were allowed to develop until they self-extinguished due to a lack of oxygen or until the fire had transitioned through flashover.
The authors report on test scenarios of fires that were allowed to develop in a variety of structures, ranging from those with no exterior ventilation to room fires with flow paths that connected the fires with remote intake and exhaust vents. Rooms of fire origin included the living room, bedroom, and kitchen. In the colonial structure, the focus was on varying the flow paths to examine the change in fire behavior and the resulting damage. Instrumentation was installed to measure gas temperature, gas pressure, and gas movement within the structures. In addition, oxygen sensors were installed to determine when a sufficient level of oxygen was available for flaming combustion. Standard video and firefighting infrared (IR) cameras were also installed inside of the structures to capture information about the fire dynamics of the experiments. Video cameras were also positioned outside of the structures to monitor the flow of smoke, flames, and air at the exterior vents. All of the fires were started from a small flaming source. The fires were allowed to develop until they self-extinguished due to a lack of oxygen or until the fire had transitioned through flashover. The times that the fires burned post-flashover varied based on the damage occurring within the structure. The goal was to have patterns remaining on the ceiling, walls, and floors post-test. Increasing the ventilation available to the fire, in both the ranch and the colonial, resulted in additional burn time, additional fire growth, and a larger area of fire damage within the structures. These changes are consistent with fire dynamics-based assessments and were repeatable. Fire patterns within the room of origin led to the area of origin when the ventilation of the structure was considered. Fire patterns generated pre-flashover, persisted post-flashover if the ventilation points were remote from the area of origin.