Sean, While that section does say "small rooms" in the 2019 edition, it was not the committee's intent to only allow different K-factor sprinklers in light hazard occupancies less than 800 sq. ft based on the definition. The language was updated for the 2022 edition to clarify that intent:
28.2.4.9.3* Sprinklers with different K-factors shall be acceptable for specific uses, such as exposure protection, small enclosures, smaller portions of a room, or directional discharge, where an adjacent sprinkler does not need to discharge as much water. Committee Statement: This change combined with better alignment of Annex material is attempting to emphasize that the identified applications are just some of the examples where different K-factor sizes can be applied. Particularly, it needs to show that this can occur within the same room without there being a change in orientation between the different sprinklers. Additionally, the reference to a Small Room is misleading since an area of up to 800 sf is not a justification for changing K-factors (nor is the restriction to light hazard applicable). As long as the change in K-Factor is not for hydraulic balancing, it is permitted. Thanks, Kevin The above is my opinion and has not been processed as a formal interpretation in accordance with the NFPA Regulations Governing Committee Projects. 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. AFSA cannot provide design or consulting engineering services, and this opinion should therefore not be considered, nor relied upon, as such. Kevin Hall, M.Eng., P.E., ET, CWBSP, PMSFPE Coordinator, Engineering and Technical Services American Fire Sprinkler Association [email protected] 214-349-5971 On Fri, Oct 29, 2021 at 10:09 AM Sean Lockyer via Sprinklerforum < [email protected]> wrote: > NFPA 13 generally discourages the use of mixing K-Factors in a system; > however, the mixing of K-Factors is allowed in certain circumstances, > namely in section 23.4.4.9.3 where it allows such use for small rooms and > enclosures. In a self-storage facility, the small 5' x 5' storage units > would not be considered "small rooms" as they are not light hazard (once > again, per the strict definition as layed out in chapter 3). However, would > you be able to consider the small units as enclosures since they are > completely separate rooms from the other, larger self-storage units ? > > Sean Lockyer > Project Designer 6817 N. Orange > Blossom Trail > Cell 386-337-1078 Orlando, > Florida 32810 > [email protected] Phone: 407-816-9101 > www.AITLifeSafety.com > > > > > > > > > > > > > > > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
