NFPA Journal - March/April 2013 - (Page 47)

Research Foundation. So far, sponsors have contributed about $700,000 to cover the costs of the tests. IKEA’s decision to work with the Foundation was based on several benefits, including the Foundation’s model of working with a technical panel to guide research projects. While independent of the NFPA process, the guidance provided by the technical panel was crucial in developing a test program that addressed the factors typically considered by the NFPA 13 Technical Committee. The Foundation also maintains a good working relationship with several fire test labs, and for this project the capabilities of Underwriters Laboratories’ (UL) large-scale test facility were essential to the test program. Devising a test program The test program was designed to investigate the rack storage of exposed expanded plastics under ceilings up to 45 feet (14 meters) high, but the majority of the tests focused on a ceiling height of 40 feet (12 meters). The technical panel considered several protection options. In general, the sponsors sought to minimize or eliminate the use of in-rack sprinklers, since they have the potential to be damaged by forklifts when commodities are loaded and unloaded from the racks, and because it can be expensive to relocate or move the pipe and sprinklers whenever racks are reconfigured. The panel discussed an enhanced in-rack sprinkler system consisting of large-orifice, extended coverage sprinklers used at a single level within a rack for spaces up to 40 feet (12 meters) tall, and preliminary testing by project sponsors indicated the potential for some extended coverage sprinklers to provide coverage for the depth of a standard double-row rack when located in the longitudinal flue space. But a desire to eliminate in-rack sprinklers led the panel to explore other options. As the panel members defined the parameters—sprinkler type and spac- Photograph: Code Consultants, Inc. Polystyrene foam meat trays were used in the tests. IKEA is considering using actual IKEA commodities in future tests to further improve the efficiency of its sprinkler systems. ing, allowable storage configurations, and so on—of a test program using ceiling-only protection, they realized from prior testing that a method would be needed to help the sprinkler system limit the horizontal spread of the fire. The panel settled on two important features: aisles that were eight feet (2.4 meters) wide and vertical barriers in the racks. Although fourfoot (1.2-meter) aisles are common in NFPA 13 protection criteria, most nonautomated warehouses require aisles wide enough for forklift access, which typically necessitates at least 8 feet. This additional distance is important in preventing a fire from spreading across an aisle. Also, prior research by IKEA and Viking Sprinkler indicated the potential for vertical barriers to slow the spread of a fire along the rack. The rack configuration was an important factor for IKEA—the company uses both standard Euro and customsize pallets and racks, while most criteria in NFPA 13 is written around North American size pallets and racks. Euro pallets are nominally 32 by 48 inches (81 by 122 centimeters), while most North American pallets are 42 inches (107 centimeters) square. Euro racks accommodate three pallet loads between rack uprights spaced at approximately every 10 feet (3.1 meters), while most North American racks accommodate two pallet loads between rack uprights spaced at nominally 8 feet (2.4 meters) on center. The depth of racks used by IKEA ranges from approximately 8 feet to 14 feet (4.2 meters), while North American double-row racks are usually less than 8 feet deep. NFPA 13 defines doublerow racks as having a total depth of 12 feet (3.6 meters) or less and considers racks with a depth greater than 12 feet to be multiple-row racks. The technical panel identified key parameters, such as the area between vertical barriers, that would allow the criteria to apply to a variety of rack configurations. The panel selected large-orifice ESFR sprinklers for the tests based on their ability to deliver substantial amounts of water in relatively large droplets into the fire plume. The rapid growth of the fire in the tests made activating too many sprinklers more of a concern than not activating the sprinklers in a timely manner, so intermediate-temperature sprinklers were selected in an attempt to limit the number of sprinklers activated. Concerns about activating additional sprinklers by skipping—a phenomenon MARCH/APRIL 2013 NFPA JOURNAL 47

Table of Contents for the Digital Edition of NFPA Journal - March/April 2013

NFPA Journal - March/April 2013
Contents
First Word
In a Flash
Perspectives
Firewatch
Research
Heads Up
Structural Ops
In Compliance
Buzzwords
Outreach
Electrical Safety
Wildfire Watch
Cover Story: Storage Occupancies
Fifty Years of Smoke Detection
Industrial Occupancies
Chicago 2013
Fire Analysis + Research
Section Spotlight
What’s Hot
Looking Back

NFPA Journal - March/April 2013