Chris, I still think that if the hydraulically most demanding area falls either between 2 systems or branch lines off 2 separate cross mains, you still need to pick up the full remote area for the area/density method. The fire will not know what sprinklers are supplied from which pipe. You still must pick up the " hydraulically most demanding area". Dewayne
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Chris Cahill Sent: Wednesday, January 13, 2010 4:41 PM To: [email protected] Subject: RE: mixed systems '02 Chapter 14.4.4 Calculation Procedure in many sections talks about systems. 14.4.4.1 - For all systems the design area shall be the hydraulically most demanding... 14.4.4.1.1.1 - Where the design is based on the density/area method...inclusion of sprinklers on both sides of the cross main. 14.4.4.1.1.3...the design area shall be extended to include sprinklers on adjacent branch lines supplied by the same cross main. Looks to me if you follow the procedure you can never get to another system or even a different set of BL's supplied from different CM on the same system. This can be used in designs. Add a CM to shorten the BL's which might be driving higher pressures. Not common I know but acceptable. We do it in really big cold boxes where grids are not allowed. 11.2.3.1.8 (1) or (2) provides for areas of sprinkler operation less than the normal 1500 or 2500. I see your point in a deluge. I don't think I ever was involved with a deluge to speak from experience. Ch. 14.4.4 only applies to the area density designs out of ch.11 and ch.12. I don't think deluge would use this chapter for the calc procedures because I don't see deluge designs in ch.12 or ch.11. 14.6 seems to say go elsewhere. What would you do where 4 systems came together at a single point? That's a lot of water...and maybe rightfully so according to the applicable standard which isn't 13. Chris Cahill, P.E. Fire Protection Engineer Sentry Fire Protection, Inc. 763-658-4483 763-658-4921 fax Email: [email protected] Mail: P.O. Box 69 Waverly, MN 55390 Location: 4439 Hwy 12 SW Waverly, MN 55390 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of A.P.Silva Sent: Wednesday, January 13, 2010 3:50 PM To: [email protected] Subject: RE: mixed systems Where does it say you calc only one system at a time. Not only you SHOULD but you HAVE to calc the entire design area. If it comes from more than one system, that is what you have to do. Some time back I was reviewing a design that had several deluge systems, but no walls between them. The designer calcd. one system at a time, and it got installed. I got to review it only after the installation. What would happen if a fire happened at the boundary of two systems. Then both systems would go off. A wet and pre-action won't be as drastic as 2 deluge systems, but still the hydraulically most demanding may be at the boundary. Tony -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Chris Cahill Sent: January 13, 2010 2:20 PM To: [email protected] Subject: RE: mixed systems I don't think we need more info. The code doesn't say anything, it's perfectly fine. Want to play games put every other line on a different system. Sprinkler code doesn't even require separations of any kind unless using a room design method. Building Code separations are beyond us contractors pay grade. And remember you only are calc'ing on system at a time. Yes a design density may have to extend 15' beyond to another system but you still only calc one system at a time. What might be interesting is say a 500 sq.ft. PA system within a regular wet. Technically you don't have to calc the extra 1,000 sq.ft. on the wet but you should. Now if she is questioning the EOR then more info is still not important nor is the code one way or another. The EOR doesn't need a reason, unfortunately. Craig's follow up comments are certainly relevant to the FPE'ing but still not related to the question does the code say no to splitting how ever you want. Smoke issue could be addressed (DIPA), wetting electrical stuff (PA with 20' overhang), oiled filled transformers might change the density but not an issue with splitting a system however you want. Chris Cahill, P.E. Fire Protection Engineer Sentry Fire Protection, Inc. 763-658-4483 763-658-4921 fax Email: [email protected] Mail: P.O. Box 69 Waverly, MN 55390 Location: 4439 Hwy 12 SW Waverly, MN 55390 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, January 13, 2010 2:59 PM To: [email protected] Subject: RE: mixed systems We need more info on what's going on and why. Craig L. Prahl, CET Fire Protection Specialist Mechanical Department CH2MHILL Lockwood Greene 1500 International Drive PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 [email protected] http://www.ch2m.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Karen Purvis Sent: Wednesday, January 13, 2010 2:55 PM To: [email protected] Subject: mixed systems Where in the code does it say that you cannot mix systems in an area. In other words if I have a large room that a section of the room is separated by a chain link fence and one side has a wet system and the other side needs a preaction system. Where does it tell me I can't do that? Karen Purvis Senior Designer Facility Systems Consultants 713 South Central Street, Suite 101 Knoxville, TN 37902 ph.865-246-0164 fax 865-246-1084 _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
