Fire Safety Science Digital Archive

The results of an experimental study of the behaviour of fully-developed fires in single compartments carried out by members of the Fire Research Working Group W14, under the auspices of the Conseil International du Batiment, are presented and discussed. The experimental work, comprising over 400 experiments shared by eight laboratories, covered a wide range of conditions, notably different shapes of compartment. The effects of scale were found to be minor, justifying the use of small-scale compartments Various relationships between the mean rate of burning (R), mean intensity of radiation and mean temperature, and parameters of the compartment and fuel are given, some derived empirically and some by a theoretical consideration of the heat balance. The values of R/AwH^1/2, where Aw is the area of the ventilation opening and H its height, were found, for small openings, to have an average value of about 0.1 kg/s m^5/2, in agreement with previous work, but a systematic trend has been found which suggests that one cannot regard this as an upper limit independent of compartment shape as the variation about the average value has been shown to be correlated with the geometry of the compartment and ventilation opening. Exploratory calculations have shown that the fire resistance required of a protected steel column is proportional to L/(AwAT)^1/2 where L is the total fire load and AT is the combined area of the compartment walls and ceiling. Large scale fire tests reported in the literature over a period of several years, some with realistic fuel systems, can also be correlated by means of this parameter although the coefficient of proportionality is somewhat lower.