Sam to answer your questions: 1. I would look at NFPA 13 and see what is the required ceiling density based on the rack storage scenario. As I said, the existing ceiling system may or may not be compliant. Start looking at this building as if it were a brand new project, define all your criteria and see what you get. Then look at it based on the existing ceiling system criteria and see if there are any options that match that criteria.
2. The area below the grating needs sprinklers. There's no way to avoid that. 3. That's a tough question without knowing what exactly you have as far as components. Are these finished circuit boards or are these miscellaneous small parts? If it's small parts then what are they made of? My first impression would be probably class II or III but electronics can vary. 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 sam b Sent: Friday, July 24, 2009 4:06 PM To: [email protected] Subject: Re: In rack sprinklers at celing level Craig As you said, I have lost my way, actually the AHJ comments were little confusing for me.. First of all they asked to provide sprinklers(in rack type) at the ceiling level of the mezzanine for the below racks. and next for some query they commented back saying inrack sprinklers cant b avoided. I think I misread that for inrack sprinklers only.(even though he mentioned clearly - positioned at ceiling). Since there was no racks at the beginning they have designed the already existing ceiling sprinklers @ 0.2 gpm/ft2 only. I have 3 issues now. 1. In case if we are providing ceiling sprinklers below mezz level and also rack sprinklers ,Does that mean that no change in the already existing ceiling sprinklers be required? 2.."""One you need to provide sprinklers below the mezzanine since the floor space is now shielded from the ceiling sprinklers."""" IS this applicable if the mezz is of grating type steel constrctn(means floor space is not fully sheilded from ceiling sprinklers)? In other wrds, can we avoid ceiling sprinkelrs below mezz level and go with only inrack sprinklers? 3.which commodity class can electronic goods(for scada panels)packed in cartons be considered? Sam On Thu, Jul 23, 2009 at 5:03 PM, <[email protected]> wrote: > >From what you've written it sounds as if you are going a different > direction than what the AHJ is requesting. From your e-mail it > appears that he is only requesting sprinklers below the mezzanine, not > in-racks. > > Now what he is asking for to be installed below the mezzanine is the > "Intermediate Style" sprinkler such as the Reliable "F-1" or Viking > VK550/560 or similar with the integral steel shield. > > Some of the things you are going to need before going much further are > the temperature of the existing ceiling sprinklers and the design > criteria of the existing ceiling sprinklers. > > Looking at Table 16.2.1.3.2 and Figure 16.2.1.3.2(b), even with > in-racks the ceiling system criteria would need to supply somewhere > between .24 and .26/2000. I'd be suspicious of a 5.6K design system > being designed to that criteria. Applying Fig. 16.2.1.3.4.1, per > Table 16.2.1.3.2 at 60% of that (somewhere around .15) the ceiling system may > work. > > So what I'm saying is you need more info. > > You have two issues. One you need to provide sprinklers below the > mezzanine since the floor space is now shielded from the ceiling sprinklers. > That's a given. Second you need to examine the need for in-rack > sprinklers. Depending on the performance of the ceiling system, how > you classify the commodity and what your design criteria will be > below the mezzanine, you may or may not need in-racks. > > > > As you would imagine, I've only spent a few minutes taking a look at > this so there may be other potential approaches that would work. But > as time is limited I leave that for you to explore. > > > > 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 sam b > Sent: Thursday, July 23, 2009 7:38 AM > To: [email protected] > Subject: In rack sprinklers at celing level > > Hiii > > > I visited a warehouse (8.6 m height) which is protected by upright > sprinklers (K-5.6) . > > Now the client have added a steel mezzanine structure with racks > above and below. > > Now local Fire authority have asked to *provide sprinklers(in rack > type) at the ceiling level of the mezzanine for the below racks.* > > ** > > Racks below will be stored with electronic good items in cartons > (mainly items for electronic panels). > > Max storage height will be 4 m. > > Their are 5 multiple row racks (2.4m wide and 9.3 m length) and 2 > single row racks of 1.2 m wide and 9.3 m length). aisle width of 1.2 m > between racks. > > > > >From NFPA ,I could see only one layer rack sprinklers enough for each > >rack > and since only 9.3 m length I need only 3 in rack sprinklers per rack. > > when the sprinklers provided at ceiling Is this the correct way forward?? > > Can we provide In rack sprinklers at ceiling in these cases? > > > > I am not finding it easy to locate the answer. > > > > Any help welcome > > > Thaanx in advance > > Sam > _______________________________________________ > 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]<to%3ASprinklerforum-reques > [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]<to%3ASprinklerforum-reques > [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)
