My understanding would be: NFPA 13, 2007, 11.2.3.3.5 (2) would allow 8' wide with a 8" lintel for light hazard Room design to be considered an unprotected opening. i.e. you could still use room design but would have to calc your 'design room' and 2 sprinklers in each of the communicating spaces (that have unprotected openings). If the door into the other room on the 3rd floor could be considered 'Non-rated automatic or self closing doors' as stated in NFPA 13, 2007 section 11.2.3.3.5 (1), had your 8" lintel opening (opening restricted to 8' wide), you could calc the sprinklers in the design room and 2 sprinklers from the floor below floor. Alternatively, since it seems you have water supply to be considering the additional sprinklers required for the communicating spaces with the room design, if you were doing .1/1500 design, would the required area of operation not be limited to a given floor and would that extra room on the 3rd floor have more than 2 sprinklers? If the 2nd room on the 3rd floor has only 2 sprinklers (depending on spacing/flow requirements), it may be comparitable to the room design you may be able to justify the calc without your friend installing auto closing doors, lintel and reducing the 12' opening. A lot of ifs for you.
Damien Shannon. -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of George Medina Jr Sent: Thursday, July 16, 2009 10:26 PM To: SprinklerFORUM@firesprinkler.org Cc: msingletonf...@sbcglobal.net Subject: Room design method - Technical information ?I am trying to help a contractor friend with a residential fire sprinkler system originally designed per NFPA-13D using Tyco 'LF-II' 4.9K. His client has areas where the beams are spaced less than 3'-6" and are 8" in Depth . He can not ( or does not) want to change the beam depth or spacing if possible so I inquired with the local AHJ about changing it to a regular NFPA-13 system and using the room design method (so as to use quick response heads near the bottom of the beams). I got the ok for that part, but the room configuration doesn't quite fit the code configuration. The most remote and demanding area is a third floor room (loft?) which has two compartments one being opened to the 2nd floor below. By reading the section on 'Room Design Method' it appears the main concern is keeping the heat in 1 room long enough to activate all the heads in it and possibly 1 or 2 heads near the unprotected opening. It appears that it would meet all other aspects of the code but the only difference being that the high room area has a 12' wide opening on the 2nd floor to an adjoin room (10' below the high ceiling). Is there a ny research data on the 'Room Design Method' where the mathematics and science required the 8" lintel and/or 8' maximum width of unprotected opening? Any suggestions? (besides walking away from it). George Medina Jr. Sr. Fire Sprinkler Designer 95-1015 Ka'apeha Pl. Mililani, HI 96819 _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: techsupp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field) __________ Information from ESET Smart Security, version of virus signature database 4252 (20090717) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 4252 (20090717) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 4252 (20090717) __________ The message was checked by ESET Smart Security. http://www.eset.com _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: techsupp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field)
