NOMENCLATURE

Due to increasing challenges in protecting high commodity storage, sprinkler designers need improved predictive tools. Actual Delivered Density (ADD) fire test data can be used to screen automatic sprinkler designs. An improved ADD fire test apparatus was developed at Underwriters Laboratories for use in developing new sprinklers for protecting high storage facilities. This paper presents the development of the apparatus and initial measurements. Calibration of the fire plume of the ADD apparatus to measurements in four tier rack storage fires indicate that fire plume temperatures and velocities are generally within 10 % of those measured in specific rack storage fires. Measured ADD values typically increase with higher sprinkler flow rates, although some sprinkler designs and ignition locations show diminishing returns