Use of Gaseous Suppression Systems in High Air Flow Environments - Phase 1

Fire Protection Research Foundation report: "Use of Gaseous Suppression Systems in High Air Flow Environments - Phase 1" (PDF, 538 KB)
Author: Eric Forssell, Jensen Hughes
Date of issue: September 2015


Information-technology and telecommunications (IT/telecom) facilities provide critical services in today’s world. From a risk standpoint, the indirect impact of fire loss due to business interruption and loss of critical operations, sometimes geographically very distant from the IT/telecom facility itself, can far outweigh the direct property loss.

In the past few years, there have been dramatic changes in the equipment housed in these facilities, which have placed increased demands on HVAC systems. As a result, engineered-airflow containment solutions are being introduced to enhance heat extraction and increase energy efficiency. From the perspective of fire-suppression system design, the use of airflow containment systems creates areas of high-air velocities within an increasingly obstructed equipment space, which could affect the effectiveness of transport of suppression agents throughout the protected volume.

Requirements related to use of gaseous-agent fire extinguishing systems in IT/telecom facilities are directly addressed by NFPA 75, Standard for the Fire Protection of Information Technology Equipment, and NFPA 76, Standard for the Fire Protection of Telecommunications Facilities. NFPA 75, 2013 edition, addresses these issues related to gaseous agent systems in several places.

  • 5.6.7 Where aisle containment systems are installed, the existing suppression and detection systems shall be evaluated, modified, and tested as necessary to maintain compliance with the applicable codes and standards.
  • 5.6.8 Where automatic sprinklers are present and the application of aisle containment systems or hot air collars creates obstructions to proper operation of sprinkler systems, the sprinkler system shall be modified as necessary to comply with NFPA 13, Standard for the Installation of Sprinkler Systems.
  • 5.6.10 If the aisle containment prevents the gaseous suppression system, where present, from producing the required design concentrations throughout the entire volume served, the gaseous suppression system shall be modified to produce the required concentration throughout the volume served.
  •* Gaseous suppression system modifications shall not be required where all the following conditions are met:
    • (1)*An automatic means of smoke detection initiates the removal of the obstruction prior to the suppression system operation.
    • (2) Removing the obstruction or portion thereof does not compromise means of egress per NFPA 101, Life Safety Code.
    • (3) The design and installation of removable obstruction elements does not diminish the level of protection below that which existed prior to the installation of the aisle containment or hot air collar.
    • (4)*The releasing devices are listed for the application.
    • (5) All removable obstructions are removed for the entire suppression zone.
  • 8.4.3 Hot aisle or cold aisle containment systems shall not obstruct the free flow of gaseous clean agent suppression systems to the IT equipment or cooling system serving the contained aisle within an information technology equipment room or zone.

Still, there are questions about the impact of the high airflows on dispersion of agent from nozzles and the impact of containment on gaseous suppression agents. The Fire Protection Research Foundation undertook a project with the goals to (a) develop an understanding of the operational features of datacenters, especially those employing “engineered-aisle-designs,” and associated elevated air flow velocities, that may pose challenges to effective transport of gaseous fire extinguishing agents in accordance with current minimum design requirements, and current field design and installation practices, (b) perform a gap analysis on the topic, and (c) develop a research plan including a recommended test plan for future work.

The Fire Protection Research Foundation expresses gratitude to the report author Eric Forssell, who is with Jensen Hughes located in Baltimore, MD, USA. The Research Foundation appreciates the guidance provided by the Project Technical Panelists, the funding provided by the project sponsors, and all others that contributed to this research effort.

The content, opinions and conclusions contained in this report are solely those of the authors.