Joe, Seems to me that this section specifically allows for your situation, then The next section directs you to the flow issue. 23.4.4.2.4 Where the available floor area for a specific area/ density design criteria, including any extension of area as required by 11.1.2 and Section 12.3, is less than the required minimum design area, the design area shall be permitted to only include those sprinklers within the available design area.
My understanding of NFPA 13 is that it is not anticipated for a wet and dry system to flow simultaneously, otherwise there would be guidance on how to handle such a situation. As far as " Not a specific type of sprinkler system" that's utter nonsense. Scenarios like yours are common place and nowhere are we directed to Do what you are being asked. The very wording of "specific area/density design criteria" lends to the Idea that there can be more than one criteria for any given area. Yours just happens to involve two different types of systems each with their own specific area/density criteria. I hope you get this worked out, Bob Knight, CET III Fire by Knight, LLC 208-318-3057 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Joe Burtell via Sprinklerforum Sent: Thursday, February 11, 2021 1:21 PM To: [email protected]; [email protected] Cc: Joe Burtell Subject: Re: Multiple System Calculation Well, I didn't get far. His response below, any suggestions? Section 23.4.4.2.4 indicates for a “specific area/density design criteria” Not a specific type of sprinkler system. The entire mechanical penthouse, both wet and dry systems, is one area/density design of ordinary hazard. So keep adding design area (Area/Density design method) until you run out of ordinary hazard or reach the minimum design area. Best regards, *Joe Burtell, SET, CFPS* [image: Burtell Fire_Small] Phone | Fax | Mobile| Text *406-204-4653 <++1-406-204-4653>* 116 N. 11th Street | Billings, MT 59101 Email: [email protected] Web Site: http://www.burtellfire.com *“**The bitterness of poor quality remains long after the sweetness of low price is forgotten.**”* *NOTICE:* The information contained in this e-mail transmission is intended only for use of the individual or entity named above. This e-mail transmission, and any documents, files, previous e-mail transmissions or other information attached to it, may contain confidential information that is legally privileged. If you are not the intended recipient of this e-mail transmission, or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that any disclosure, dissemination, distribution, copying or other use of this transmission or any of the information contained in or attached to this e-mail is strictly prohibited. If you have received this e-mail transmission in error, please immediately notify us by return e-mail transmission and destroy the original e-mail transmission as well as its attachments without reading or saving it in any manner. Thank you. On Thu, Feb 11, 2021 at 12:39 PM Joe Burtell <[email protected]> wrote: > Thanks, guys, that is what I was thinking as well. > > Best regards, > > *Joe Burtell, SET, CFPS* > > [image: Burtell Fire_Small] > > Phone | Fax | Mobile| Text *406-204-4653 <++1-406-204-4653>* > > 116 N. 11th Street | Billings, MT 59101 > > Email: [email protected] > > Web Site: http://www.burtellfire.com > > *“**The bitterness of poor quality remains long after the sweetness of > low price is forgotten.**”* > > *NOTICE:* The information contained in this e-mail transmission is > intended only for use of the individual or entity named above. This e-mail > transmission, and any documents, files, previous e-mail transmissions or > other information attached to it, may contain confidential information that > is legally privileged. If you are not the intended recipient of this > e-mail transmission, or the employee or agent responsible for delivering it > to the intended recipient, you are hereby notified that any disclosure, > dissemination, distribution, copying or other use of this transmission or > any of the information contained in or attached to this e-mail is strictly > prohibited. If you have received this e-mail transmission in error, please > immediately notify us by return e-mail transmission and destroy the > original e-mail transmission as well as its attachments without reading or > saving it in any manner. Thank you. > > > On Thu, Feb 11, 2021 at 12:24 PM Bob Knight via Sprinklerforum < > [email protected]> wrote: > >> Joe, >> The AHJ's interpretation sounds incorrect. What is supposed to take >> place is as follows: >> 23.4.4.2.5 Where the total design discharge from these operating >> sprinklers is less than >> the minimum required discharge determined by multiplying the required >> design density >> times the required minimum design area, an additional flow shall be added >> at the point of >> connection of the branch line to the cross main furthest from the source >> to increase the overall >> demand, not including hose stream allowance, to the minimum required >> discharge. >> >> In other words, we are now required to add additional flow to >> calculations when we are in a situation like yours. >> The minimum required flow for a 1500 sf design area for OH1 is 210 gpm, >> and the minimum required flow >> For 1950 sf is 292.5 gpm. If your areas are not flowing these minimus >> you will need to add the additional flow >> as stated above. It's a pain in the neck but other than one more step in >> the calc that's it. >> >> Thank you, >> >> Bob Knight, CET III >> Fire by Knight, LLC >> 208-318-3057 >> >> -----Original Message----- >> From: Sprinklerforum [mailto: >> [email protected]] On Behalf Of Joe Burtell >> via Sprinklerforum >> Sent: Thursday, February 11, 2021 11:47 AM >> To: [email protected] >> Cc: Joe Burtell >> Subject: Multiple System Calculation >> >> I have a situation where an engineer is telling me I have to calculate a >> wet and dry system together because neither space meets the 1500 s.f >> minimum. I have a penthouse mechanical room OH 1 (WET) of 1014 s.f. and an >> adjacent room OH1 (DRY) of 469 s.f. I have calculated each room separate >> of >> each other. There is a full-height wall with a door that separates the >> rooms. The wall and door are not fire rated, so the large room method is >> out. This does not make any sense to me. Any sections that would >> require this to be done. He is saying 11.1.2 of NFPA 13 2016 requires it. >> I >> argue exception #2 says it does not apply. >> >> Best regards, >> >> *Joe Burtell, SET, CFPS* >> >> [image: Burtell Fire_Small] >> >> Phone | Fax | Mobile| Text *406-204-4653 <++1-406-204-4653>* >> >> 116 N. 11th Street | Billings, MT 59101 >> >> Email: [email protected] >> >> Web Site: http://www.burtellfire.com >> >> *“**The bitterness of poor quality remains long after the sweetness of low >> price is forgotten.**”* >> >> *NOTICE:* The information contained in this e-mail transmission is >> intended only for use of the individual or entity named above. This >> e-mail >> transmission, and any documents, files, previous e-mail transmissions or >> other information attached to it, may contain confidential information >> that >> is legally privileged. If you are not the intended recipient of this >> e-mail transmission, or the employee or agent responsible for delivering >> it >> to the intended recipient, you are hereby notified that any disclosure, >> dissemination, distribution, copying or other use of this transmission or >> any of the information contained in or attached to this e-mail is strictly >> prohibited. If you have received this e-mail transmission in error, >> please >> immediately notify us by return e-mail transmission and destroy the >> original e-mail transmission as well as its attachments without reading or >> saving it in any manner. Thank you. >> _______________________________________________ >> 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 >> > _______________________________________________ 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
