Rates of 'production' of hot gases in roof venting experiments

Abstract In Europe the design of systems for venting large fires generally employs a simple empirical equation for the mass rate of production of hot gases, M, by a fire M = 0.188Py 3 2 ( kg/s ) where P is the perimeter of the fire and y is the height of the bottom of the layer of hot gases above the floor. It is shown in this paper that it gives a better fit to the results of experiments on roof venting than some other correlations which are more soundly-based theoretically but relate to measurements in different experimental situations. It is suggested that it should continue to be used for the design of practical roof venting systems.