Study on downward flame spread over extruded polystyrene foam in a vertical channel: Influence of opening area

Abstract

Summary Experimental methods and theoretical analysis are employed to investigate effects of channel opening area on downward flame spread characteristics of extruded polystyrene (XPS) thermal insulation materials on building facade. The average flame height first drops and then rises as dimensionless opening area (the ratio of sidewall opening area to sidewall area, ie, S*) increases. As S* rises, both the average and maximum temperature of the curtain wall decrease, and the decreasing of the average temperature is linear. XPS surface temperature history can be divided into four stages, ie, inapparent rising stage (preheating), significant rising stage (melting), dropping stage (pyrolysis), and rerising stage (ignition). The preheating length first rises and then drops as S* increases. The XPS flame spreads steadily at the early period while acceleration occurs at the later period. For different opening areas, the difference in spread distance history is not apparent in the early stage while this difference is significant in the later stage. The flame spread rate (Vf) first increases and then decreases as S* rises. A downward flame spread model for XPS in vertical channel with openings is built. The varied trend of Vf predicted using this model corresponds to the experimental result.

Effects of Overlap Length on Flammability and Fire Hazard of Vertical Polymethyl Methacrylate (PMMA) Plate Array

“…Firstly, a partially enclosed vertical channel is formed when two adjacent plates overlap with a certain spacing, and thus the stack effect occurs, which could promote the air flow in the channel. According to An et al's work [24], the flow velocity of the induced airflow in the vertical channel is:…”

Fire Spread of Thermal Insulation Materials in the Ceiling of Piloti-Type Structure: Comparison of Numerical Simulation and Experimental Fire Tests Using Small- and Real-Scale Models

“…Consequently, ceiling and thermal insulation materials are applied to reduce heat flows by conduction, convection, and radiation in building structures. However, these materials are mostly organic in nature, which are easily ignited and generate large volumes of toxic gases like CO and CO 2 during combustion, thus increasing the casualties in the event of a building fire [1][2][3][4]. Furthermore, even though there are legal standards about the flame-retardant performance of thermal insulation materials, there is insufficient research on the correlation between the flame-retardant performance of thermal insulation materials and the on the correlation between the flame-retardant performance of thermal insulation materials and the fire hazards of buildings.…”

“…Furthermore, even though there are legal standards about the flame-retardant performance of thermal insulation materials, there is insufficient research on the correlation between the flame-retardant performance of thermal insulation materials and the on the correlation between the flame-retardant performance of thermal insulation materials and the fire hazards of buildings. Thus, materials with low flame-retardant performance have been used in buildings, causing many incidents of fire spread [1][2][3][4].…”

Performance of fire breaks installed within EPS‐insulated façade systems

“…4,5 Studies investigated the potential of downward flame spread, the effect of insulation thickness, or the influence of the substrate. [6][7][8] The fire incidents where ETIC systems were involved are generally considered examples where materials (or installation methods used) would not be expected to meet regulatory requirements or test criteria in countries with specific requirements for combustible facades. 9 Reported fire incidents, as well as existing research, show that the key initiation event of a fire involving exterior walls is interior fires spreading to external wall systems via external openings such as windows.…”