Fire Performance Evaluation of Nominal K=5.6 Ceiling Sprinklers for Protecting 8-ft. High Storage of Paper Files in Compact Mobile Shelving Under a 10-ft. Ceiling

Fire Protection Research Foundation report: "Fire Performance Evaluation of Nominal K=5.6 Ceiling Sprinklers for Protecting 8-ft. High Storage of Paper Files in Compact Mobile Shelving Under a 10-ft. Ceiling" (PDF, 3 MB)
Author: Underwriters Laboratories Inc.
Date of issue: June 2008 

Executive Summary

A series of five (5) bench-scale and two (2) large-scale fire tests was conducted to develop data regarding the level of protection provided by nominal K-5.6 (gpm/psi ½) pendent, quick response ceiling sprinklers in protecting an arrangement of paper in standard manila paperboard folders stored in moveable compact mobile shelving units to a nominal height of 8- ft.

Bench-scale testing consisted of a single 36-in x 24-in x 9.75-in sheet metal shelf loaded with varying densities of commodity. A total of five bench-scale fire tests were conducted on a load cell beneath a calorimeter where total heat release rate was measured over the course of each test. Based on the results of these bench-scale tests, the project consulting engineers determined that a 70% loading density by volume would be used as the basis for both large-scale fire tests.

The tests were conducted under a 10-ft high ceiling with 155°F pendent ceiling sprinklers installed on 15 by 15-ft. spacing with the deflectors positioned 8- in. below the ceiling. The first large-scale test was conducted with the moveable compact mobile shelving units in the open position, including a 3- ft. center aisle. The second large-scale test was conducted with the moveable compact mobile shelving units in the closed position, and included full-height longitudinal sheet metal barriers in two of the four 24- in deep moveable shelving units.

For both large-scale tests, the ceiling sprinkler system was supplied with water resulting in a nominal sprinkler discharge density of 0.10 gpm/ft2. The ignition location for each of the two tests was located between four sprinklers.

The large-scale fire tests utilized both moveable and fixed compact shelf units. The individual shelving fixtures in the moving units of the systems were nominally 3- ft wide, 2- ft deep, and 8-ft tall. Vertical transverse sheet metal barriers were provided between each of the five (5) storage bays at 3- ft. intervals. There were eight (8) shelf levels positioned with a nominal vertical spacing of 8, 18.5, 29, 39.5, 50, 60.5, 71, 81.5 and 95-in. from the floor. There were five (5) shelf fixtures in each row with a total length of 15- ft.

For the first large-scale fire test, an open shelving arrangement was used consisting of six compact shelf units. Five of the compact shelf units were moveable. Four of the moveable units were approximately 24-in. deep and one moveable unit was approximately 12- in. deep. The sixth compact shelf unit was fixed and approximately 12-in. deep. The compact shelf configuration was open with a 36-in aisle space provided in the center of the array. No longitudinal barriers were provided. The target arrangement consisted of cardboard fixed to upright structures. The paper-faced cardboard was positioned across a 36- in. aisle space on the north, south, east and west sides of the compact shelving array. The cardboard affixed to the target assembly spanned 16- ft. long x 8- ft high.

The first large-scale fire test was conducted for 90 minutes (90:00) as requested by the project consulting engineers. A total of thirteen (13) ceiling sprinklers operated during the 90-minute test period. The fire in Test 1 propagated to the east, west and south ends of the main shelving array. However, the fire was contained within the main shelving units and did not spread to the adjacent targets.

For the second large-scale fire test, a closed shelving arrangement was used consisting of five moveable compact shelf units in the main array and one fixed compact unit as a target. Four of the moveable units were approximately 24-in. deep and one unit was approximately 12-in. deep. Full height longitudinal sheet metal barriers were installed in two of the four 24-in deep moveable units. The sixth compact shelf unit was a target which consisted of a 12- in. deep compact shelving unit positioned across a 36-in aisle on the north side, filled to the same capacity of the main shelving array. Cardboard fixed to upright structures were also placed across a 36- in. aisle space on the south, east and west sides of the compact shelving array. The cardboard target assemblies spanned 16- ft. long x 8- ft. high.

The second large-scale fire test was conducted for 82 minutes (82:00) as requested by the project consulting engineers. A total of four (4) ceiling sprinklers operated during the 82-minute test period. The fire in Test 2 propagated to the east and west ends of the array, but was generally limited to the area between the full-height longitudinal sheet metal barriers. The fire was contained within the main shelving units and did not spread to the adjacent target arrays.