Sectional fire protection for attic spaces

#The present disclosure relates generally to fire protection systems and more specifically to fire protection systems for the protection of attic spaces.

#Under the fire protection industry standard, National Fire Protection Association NFPA 13: Standard for the Installation of Sprinkler Systems, (2013 ed.), criteria is specified for the installation of fire protection sprinkler systems for attic spaces. The installation criteria can include sprinkler spacing and location requirements and application density requirements for sprinklers in order to protect attic spaces with peaked or sloped roofs including protection of the eaves regions, the eaves corner and the areas along the base. Current attic fire protection systems employ “automatic sprinklers.” NFPA 13 defines an “automatic sprinkler” as “a fire suppression or control device that operates automatically when its heat-activated element is heated to its thermal rating or above, allowing water to discharge over a specified area.” The installation requirements can require that automatic sprinklers be installed in each of the peak and eaves regions in order to provide for the designed fire protection including satisfaction of, for example, the 0.1 gallon per square foot (0.1 GPM/SQ. FT.) density requirement.

#Attic space can be defined by the intersection of the joists of the roof deck with the joist of the base or ceiling deck and the rise-to-run ratio or pitch from the intersection to the peak of the roof. For the purpose of designing for fire protection of the attic space, the eaves region of the pitched roof can be the triangular sections at the outer edge of the attic space and lateral of the roof peak when viewed in elevation. Moreover, for the purpose of fire protection of the eave region, the eaves region can be defined by the intersection of the roof and ceiling joists and the distance to the first sprinkler disposed medially of the intersection. The location of this first medial sprinkler relative to the intersection defines the vertical of the eaves region to the ceiling deck and the horizontal of the eaves region along the ceiling deck. The location of the first medial sprinkler relative to the intersection of the roof and ceiling joists also defines the hypotenuse of the triangular eaves region in the direction of the sloping roof joists. Section 8.6.4.1.4.3 of NFPA 13 specifies that, fora roof slope of 4 in 12 or greater, the first medial sprinkler is not to be less than five feet (5 ft.) from the intersection of the roof and ceiling joists in the direction of slope. It is believed that, in order to satisfy the preferred 0.1 gpm/sq. ft. density, the first medial sprinkler in known systems using only automatic sprinklers is located at a maximum distance from deflector to the roof ranging from 1 inch to a 22 inches. These current system requirements can pose various problems for complying with design and installation requirements due to unforeseen obstructions and thermal dynamics including, for example, fire growth patterns and the limited thermal responsiveness of automatic sprinklers. For example, automatic sprinkler installation and spacing which locate sprinklers at the five foot minimum distance from the roof and ceiling joist intersection for protection of the eave regions can require installations in low clearance areas below the roof. Additionally, the number of sprinklers in the peak and the eaves contribute to the overall fluid or water demand of the system.

#FIG. 1A is a schematic elevation view of a preferred sectional fire protection system for an attic space.

#FIG. 1B shows a schematic plane view of the system of FIG. 1A.

#FIG. 2 is a detailed view of an installed fluid control thermal detection device in the system of FIG. 1A.

#Shown in FIGS. 1A-1B is a preferred embodiment of a sectional fire protection system 10 for the protection of a combustible concealed space between a roof deck R and a ceiling base C and more preferably a fire protection system for the protection of an attic space ATTIC. The roof deck R is preferably sloped toward a ridge formation RD to define a slope (rise:run) of 2:12 or greater, preferably 4:12 or greater such as, for example, 8:12, 10:12 and even more preferably 12:12. The roof decks described herein can include two or more portions which slope toward and intersect at the ridge line or formation RD. Although the two portions R1, R2 of the roof deck R are shown as having equal slopes, it should be understood that the two portions can define different slopes. Extending from the roof deck at or proximate the ridge formation RD can be one or more baffles. The baffles can be in the form of, for example, shear walls or draft curtains DC, as seen for example in FIGS. 3D-3E, to divide the attic space ATTIC into two or more section or zones. The one or more baffles can extend parallel to the ridge formation RD or alternatively, extend perpendicular to the ridge formation RD in a spaced apart arrangement. Moreover, the baffle can extend from the roof deck all the way to the ceiling base or extend down to a distance spaced from the ceiling base. An exemplary attic space ATTIC is further defined by a span S of the horizontally extending ceiling base C and outer eaves region(s) E. Preferred systems described herein preferably protect attic spaces or portions thereof having a span S of no more than eighty feet (80 ft.), such as fur example, up to sixty feet (60 ft.); up to forty feet (40 ft.), up to twenty feet (20 ft.) or less.

#In the elevation view of the attic space ATTIC and preferred embodiment of the fire protection sectional system 10 in FIG. 1A, the outer eaves regions E can include a first eave region E1 and second eave region E2 disposed laterally about the ridge formation RD and a peak region P. As used herein, a “peak region” P is defined as a high point in the attic space ATTIC beneath a roof deck either along a ridge formation, at the intersection of two or more ridge formations or along the intersection between a roof deck and a draft curtain. Each of the eaves regions E1, E2 is defined by the intersection EC of the roof deck R and ceiling base C. Each of the eaves regions E1, E2 can be further defined by the linear distance to a firefighting fluid distribution device 30 disposed medially of the intersection EC in the direction from the intersection EC to the peak P either measured parallel to the roof deck R or the ceiling base C. Alternatively, the eaves regions E1, E2 can be defined by a minimum vertical height from the ceiling base C to the fluid distribution device 30.

#Generally, the preferred sectional fire protection system 10 includes one or more fluid control thermal detection device(s) 20 proximate the peak region P which delivers a firefighting fluid to one or more fluid distribution devices 30 as a controlled response upon detecting one or more products of combustion in the peak region P. The fluid distribution devices 30 are preferably pipe connected to the fluid control thermal detection devices 20 in an open state and spaced about the attic space ATTIC to distribute the firefighting fluid and provide for wetting of surfaces and to address the detected fire and even more preferably suppress the fire. As described herein, the fluid distribution device 30 can be embodied as a fire protection sprinkler, a fire protection nozzle or any other fluid carrying conduit capable of dispersing firefighting fluid in a manner described herein. Depending upon its type, the device 30 can include a fluid deflector or diffuser to define a coverage area of the device 30. Because the fluid distribution devices 20 are connected in an open state to the fluid control device 30, the preferred system 10 thus provides for one or more deluge sub-system(s) for sectional fire protection of the attic spaces ATTIC in which fluid delivery control and fire detection are coupled together and located in the region of the attic in which the products of combustion collect, i.e., in the peak region P. By employing a deluge configuration to protect the attic space, the preferred system 10 separates the fire detection and fluid distribution between distinctly located components of the system so as to overcome the problems encountered in known attic fire protections systems generated by the fire dynamics in attics.