I think what Ron is implying is that the shell system is designed for one thing, but the tenant later comes in and puts in solid shelves or adds heads under ductwork. The original system was designed, reviewed, approved, installed, inspected and accepted per NFPA and local requirements. When the TI contractor comes in later down the road (1 day - 10 years later, who knows), they often do not do the due diligence to calculate the extra heads under obstructions.
If a contractor is to bid a shell system with 14 heads flowing vs 12 heads, they may as well not even bid. You have bigger pipes and possibly a bigger pump. While 14 may be the prudent thing to do, you have to also go with practical. Why calculate the system to 14 heads if the tenant never has additional heads due to obstructions or other items? -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Hewitt Sent: Wednesday, November 05, 2008 9:08 AM To: [email protected] Subject: RE: ESFR Heads below obstructions So, that makes it ok, then? You know better, but you go ahead and do it wrong anyway? Jeff Hewitt, PE, SET, SFPE (Professional Member) Corporate Engineer Bi-State Fire Protection Corporation 241 Hughes Lane St. Charles, MO 63301 636-946-0011 636-946-5172 (FAX) -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Fletcher, Ron Sent: Wednesday, November 05, 2008 7:25 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) > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.8.6/1765 - Release Date: 11/3/2008 4:59 PM > > > > _______________________________________________ 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 3580 (20081103) 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) _______________________________________________ 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) __________ NOD32 3586 (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)
