I thank the participants in this discussion. It was most helpful.
To summarize: NFPA 13 2002 requires 14 heads for hydraulic calc if there are sprinklers below obstructions. NFPA 13 2007 omitted this specific statement. Quote: 14.4.3 The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines. 14.4.4 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. The good handbook as quoted below interprets it as specified in NFPA 13 -2002. Thanks again. Dan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, November 05, 2008 16:19 To: [email protected] Subject: RE: ESFR Heads below obstructions NFPA 13 Handbook, 2007 edition, section 14.4.4 has a FAQ on this: "FAQ - Where additional ESFR sprinklers are added below obstructions, what is the total number of sprinklers that must be calculated?" Response to FAQ: "Additional ESFR sprinklers installed below fixed obstructions, as required by the obstruction provisions of Chapter 8, must be included in the hydraulic calculations. Subsection 14.4.4 requires that up to an additional two ESFR sprinklers located below obstructions be included with the 12 ESFR sprinkler calculations for a total of up to 14 ESFR sprinklers. The maximum of two additional ESFR sprinklers applies regardless of the number of ESFR sprinklers installed below obstructions in the remote area. Where only one additional ESFR sprinkler is needed to address an isolated obstruction, only that one ESFR sprinkler needs to be added to the calculation. Care must be taken to identify the appropriate hydraulic remote area when such additional ESFR sprinklers are installed below the fixed obstructions. The additional two ESFR sprinklers need only to be added to the 12 ESFR sprinkler demand directly above the obstruction when the combined number of sprinklers creates the hydraulically most demanding area." The same FAQ and notes are shown for other sections listed below. Hope that helps some. Andrew Weisfield "danarbel" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 11/05/2008 08:55 AM Please respond to [email protected] To <[email protected]> cc Subject RE: ESFR Heads below obstructions It has nothing to do with competiveness. I'm not a contractor. It is a matter of replacing a public supply with A 1500gpm pump and 350cum Tank. Not a small change. Dan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: 05 November, 2008 3:34 PM To: [email protected] Subject: RE: ESFR Heads below obstructions Really? Two heads will keep you from being competitive? That must be some real close bidding. 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 Fletcher, Ron Sent: Wednesday, November 05, 2008 8:25 AM To: [email protected] Subject: RE: ESFR Heads below obstructions If you add the flow of two additional heads below obstructions you won't be low bid. The added flow will probably drive your main sizes up a pipe size and it may affect the fire pump as well. It isn't all that dissimilar to storage racks. We know if racks with solid shelves are added to a warehouse the flow for the in-rack sprinklers would have to be added into the roof calc yet we don't make an allowance for them in the shell system, at least we don't. Around here TI contractors chop up ESFR systems by adding heads at demising walls and under ducts but they don't do a new roof system calc. I would bet that 8 out of 10 ESFR systems in Phoenix don't calc after TI but AHJ's around here either don't care or more likely don't know. Ron Fletcher Aero Automatic Phoenix, AZ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of danarbel Sent: Tuesday, November 04, 2008 2:48 PM To: [email protected] Subject: RE: ESFR Heads below obstructions Well, I read all that and it seems that all you need are 12 heads Dan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: 04 November, 2008 7:28 PM To: [email protected] Subject: ESFR Heads below obstructions Dan, All references here are from the '07 edition of NFPA-13: 14.4.4 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. 15.4.4 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. 16.2.3.5 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations 16.3.3.6 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. 17.2.3.4 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. 17.3.3.5 Where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers for one of the levels shall be included with those of the other level in the hydraulic calculations. 22.4.4.6.4 The requirements of 22.4.4.6.1 to include every sprinkler in the design area to be included in the system discharge shall not apply; where ESFR sprinklers are installed above and below obstructions, the discharge for up to two sprinklers from one of the levels shall be included with those of the other level in the hydraulic calculation. Based on what I read in the ROP just published it doesn't look like any of these have been removed, although it appears that the wording in 22.4.4.6.4 has been moved around a bit, and a new 22.4.4.6.4.1 has been added (See 13-462, Log CP82 in the ROP) Hope that is what you were after. * *PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> e-mail www.ParsleyConsulting.com <http://www.ParsleyConsulting.com> website danarbel wrote: > Question regarding the number of ESFR heads required for hydraulic calc. > > The nominal number is 12. > > There was a requirement to add 2 heads if there are heads installed below > beams or AC ducts. > > If I'm not wrong the addition of 2 heads was abolished. > > Please confirm or correct me, > > Dan Arbel > _______________________________________________ Sprinklerforum mailing list http://lists.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) __________ NOD32 3585 (20081105) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com _______________________________________________ Sprinklerforum mailing list http://lists.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) This email is intended for named recipients only. _______________________________________________ Sprinklerforum mailing list http://lists.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 http://lists.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)
