Light Obstruction Residential Sprinklers
“The sprinkler spacing from ceiling construction such as light fixtures in NFPA 13D in Sections 8.2.5.1.1, 8.2.5.1.2, 8.2.5.1.3 indicates that sprinklers shall be located a minimum of 3 ft from the obstruction with 3 ft measure being measured from the sprinkler to the center of the obstruction. Can the measurement be taken as specified in NFPA 13D for NFPA 13 residential applications?” We have reviewed the 2016 edition of NFPA 13 and NFPA 13D as the applicable standards. Our informal interpretation is that the requirements of NFPA 13 shall be applied. The NFPA 13 and NFPA 13D standards approach light fixtures differently. The two documents are intended to be standalone standards. As such, the requirements of NFPA 13D cannot be applied in lieu of NFPA 13. The type of light fixtures installed for NFPA 13D applications are seldom known at the time of installation. Pendent sprinklers are located at least 3 ft away from obstructions such as ceiling fans and light fixtures and the distance is measured from the center of the sprinkler to the center of the obstruction. NFPA 13D is an economical approach to reduce injuries and improve life safety in the event of a fire. NFPA 13 measurement differs where the distance needs to be measured from the center of the sprinkler to the nearest edge of the obstruction. The obstruction rule of Section 8.10.6.2.1.3 is applied where sprinklers are positioned away from obstructions a minimum distance of four times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures). This section goes on to clarify that the maximum clear distance required to obstructions in the horizontal orientation (e.g., light fixture and truss chords) shall be 36 in. One could argue the types of fixtures are not known at the time of installation for NFPA 13 installations. That could be true, but the type of fixture should be determined prior to installation. Since NFPA 13 addresses property protection that results in providing life safety, the obstruction rules are more stringent than the NFPA 13R and NFPA 13D standards. ------------ Technical Update is prepared by the Technical Services Dept. of the AFSA: Roland Huggins, a PE registered in fire protection engineering, Vice President of Engineering and Technical Services; and Tom Wellen, a PE registered in fire protection engineering and Tom Noble E.T., a Technical Programs Specialist. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright 2017, American Fire Sprinkler Association. All Rights Reserved. Ada Dickson Ada Dickson Administrative Assistant Technical Services Dept. PH: (214) 349-5965 ext. 124 Fax: (214) 343-8898 E-mail: [email protected] -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.firesprinkler.org/private.cgi/sprinklernotes-firesprinkler.org/attachments/20170227/30dbe44a/attachment.htm>
