Wow. We are doing a project with a canopy that I don't think needs to be sprinkler but that isn't the point. The canopy is 3'-11" wide, sloped greater than 2 in 12, requires a dry system and is 600' long. Section 11.2.3.4.2 requires 7 heads maximum. Would 23.4.4.1.1.4 apply and if so how would it be applied? The minimum design area would be 0.20 gpm over 2,535 sqft. The canopy is 2,400 sqft and only has one branch line with 48 sprinklers.
Ron F -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ed Kramer Sent: Wednesday, March 13, 2013 6:51 PM To: [email protected] Subject: RE: Phantom Flow Chris, the way I read 23.4.4.1.1.4 is that it's optional. In your case, I'd calc 2,000 sf of dry system plus 1,900 sf of wet. Since it's all light hazard, it shouldn't get ugly. I gotta believe there will be some tweaking to that section, though. I read the ROP and ROC - Tracey's 480 sf canopy (page 88 of the ROC) is probably being protected by 4 sprinklers, but could require a 4" supply pipe & dry valve since the phantom flow is added at the end of the dry x-main. That doesn't seem reasonable to me. Ed Kramer Lawrence, KS > -----Original Message----- > From: [email protected] [mailto:sprinklerforum- > [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 > > > > > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: > <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/atta > ch ments/20130313/26a3e378/attachment.html> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
