You cannot always apply the most demanding room - especially in OH occupancies....seems like a BIG mess to me. I say this sincerely, I cannot see the logic here and would love to understand what this is trying to accomplish. Greg
On Thu, Mar 14, 2013 at 11:12 AM, Mark A. Sornsin, P.E. < [email protected]> wrote: > This strikes me as overthinking run amok. I'm surprised it made it > through to the final document. Is the logic that the area/density method > requires flowing over the entire area? Thus, if your area is smaller than > the required area you have a choice: use room design method, or add this > phantom flow. > > Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection > Engineer | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | > http://www.kfiengineers.com > > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Cahill, Christopher > Sent: Wednesday, March 13, 2013 4:46 PM > To: [email protected] > Subject: Phantom Flow > > Not what you think by the subject. Working out of NFPA 13 '13 > 23.4.4.1.1.5. This is new and confusing us greatly. > > I have a 20,000 sq.ft. heated LH building. And a 2,000 sq.ft. area that > needs a dry system. Not an auxiliary dry system. My starting required > design is 0.1/3,900. I calc the system at 2,000 sq.ft. (cuz that's all I > have) and get for discussion sake 220 gpm. Then I subtract from 390 (3,900 > x 0.1 per 23.4.4.1.1.5) and I get 170 gpm. Then I go back to the calc and > redo but this time I add 170 at the end of the main. Now this has the > effect of overflowing all the rest of the BL's such my final calc is more > than 390. > > !@#$^# > > What if I have a 500 sq.ft. building and the next building is 20 miles > away @#$@# are we calc'ing this extra area for? > > Can someone 'splain if we got it right and then why in the world this got > into the standard? > > Chris Cahill, PE* > Senior Fire Protection Engineer, Aviation & Facilities Group Burns & > McDonnell > 8201 Norman Center Drive > Bloomington, MN 55437 > Phone: 952.656.3652 > Fax: 952.229.2923 > [email protected]<mailto:[email protected]> > www.burnsmcd.com<http://www.burnsmcd.com/> > > Proud to be one of FORTUNE's 100 Best Companies to Work For *Registered > in: MN > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- Greg McGahan Living Water Fire Protection, LLC <http://www.livingwaterfp.com> 1160 McKenzie Road Cantonment, FL 32533 850-937-1850 fax 850-937-1852 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20130314/ea86d971/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
