Damien, I can't give you any direct cites of the standard or of testing which references why the reduction for use of high-temp sprinklers is allowed by NFPA-13.
However, in the '10 edition, there are several sections which can give you some idea of how that allowance is supported by testing and analysis of that testing. I realize fully that you're talking about an extra hazard occupancy, rather than storage, but the information on storage protection at heights less than 25'-0" high suggests that fewer high-temp sprinklers would be necessary to control a fire at the same efficiency than would ordinary temp sprinklers. Support for this can be found in A.12.6, A15.2.2, A19.1.2.1.4, C.14, and C.23. While some of that information in those annex sections can get pretty detailed and complex, the information is fairly clear in support of that allowance. I don't know the science behind that allowance, but my thoughts are that during the early stages of a fire in an EH or storage occupancy < 25' high, when using high temp sprinklers, that there would be fewer sprinklers activating which did not have controlling effects on the fire, and it would increase the efficiency of the sprinklers which did operate by not "starving" water and pressure from direct application on the fire. That's probably not a good explanation, but it's the best one I could come up with before breakfast on Sunday morning. Hope those sections can give you some guidance to what you're looking for. 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 Damien Shannon wrote: > Dear forum members, > > While attending Cecil's recent hydraulic calculation seminar (Awesome!), I > was reminded of the allowance for the remote area reduction for high > temperature sprinklers in extra hazard occupancies. > > I have a project with a specification for ordinary temperature sprinklers > for an extra hazard area. I plan on submitting an RFI to the project > engineer to see if the area could be reduced using high temperature > sprinklers. In order to make everyone feel warm and fuzzy about the > reduction I was hoping to get some background on how the reduction for high > temperature sprinklers came about. > > My theory is that the original area densities were derived from initial > testing with Ordinary temperature sprinklers and that some years latter > testing with high temperature sprinklers indicated that the effectiveness of > the higher temperature sprinklers was superior. > > Can anyone confirm/dismiss this theory or provide any other insight on this > reduction? (year of testing/who performed testing, etc) > > As always thank you very much for your insight! And thank you Cecil for the > numerous nuggets of info in the seminar! > > Damien Shannon. > > _______________________________________________ > 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) > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.441 / Virus Database: 271.1.1/2993 - Release Date: 07/10/10 > 06:36:00 > > _______________________________________________ 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)
