Inert gas extinguishing systems: Standard and non-standard suppression testing

Total flooding inert gas extinguishing systems are used to protect facilities that cannot use water-based systems, such as in server rooms and computing facilities. While the standardized approval test for these systems utilizes a wooden crib and three arrays of plastic sheets to represent real-world combustibles, questions remain about the applicability of the Standardized Total Flooding Test results to the real world. Further, defining extinction within the context of inert gas discharge systems is difficult, and often, visual observations are used. To assess the Standardized Test methodology and investigate the extinction dynamics of inert gas systems, burning standard wood cribs, nonstandard wood cribs, polymeric materials, intact desktop computer towers, and an intact server were exposed to total flooding inert gas discharges. To test the limits of extinction, two nonstandard discharge periods, 41 s and 285 s, were utilized in addition to the standard 60 s and 120 s discharge periods. Testing was performed in a full-scale 100 m 3 compartment and a recently developed reduced-scale 33 m 3 enclosure. The average oxygen extinguishing concentration for each test article was measured, and an analysis of the extinction dynamics is presented. • Inert gas suppression testing with nonstandard discharge periods. • Design and analysis of nonstandard wood cribs. • Suppression testing with intact desktop computer towers and a server. • Analysis of extinction dynamics.