Please excuse my contractors cynicism but could it be that QR's are more expensive than SR's? What organization requested and paid for the testing to justify the reduction and why? Could it be that an area reduction results in smaller pipe size at less cost to justify the more expensive sprinkler? If there was a problem with the reaction time of SR heads in light hazard then make the change but why the area reduction?
We do have 225 sqft OH sprinklers, they are called ECOH. It's Friday and our daily highs are below 100F. Ron F -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of rongreenman . Sent: Thursday, October 03, 2013 6:50 PM To: [email protected] Subject: Re: Spacing Rules Well, now that you two have hijacked my thread.... This was a question about philosophy and history, not math and time. Let's try again, and the bathroom compartmentalization thread is similar to what I'd like some feedback on. Most discussion about spacing rules revolve around arguments relating to distribution. I'm wondering how many are based on heat detection. For instance, why can I use an XYZ SSP head to cover 225 sq in light hazard but not ordinary. Since I'm after density over square footage I can certainly accomplish this prohibited feat. But after a given edition we are suddenly required to use QR heads for light hazard for some unspecified reason. That certainly doesn't have anything to do with coverage. On Thu, Oct 3, 2013 at 10:11 AM, Brad Casterline <[email protected]>wrote: > Yes, and by 'different fire curves' I assume you mean fire growth rates. > I want to model the four common 'design fires': SLOW, MEDIUM, FAST, > and ULTRAFAST. All four will be "T-Squared", which as you know means > the growth is proportional to the time squared. I am not sure what the > proper word is for the factor that distinguishes SLOW from FAST but I > know what the numbers are and how to calc how many seconds from > ignition to peak RHR (Rate of Heat Release). I want to find out what > this "...same RHR point..." is. I will have to run (8) scenarios > because I want to use two separate max RHR. I will use 1250 kW and > 2500 kW. The factor I use for FAST, for example, is .0466 kW/sec2. So > a 2500 kW T-Squared FAST fire would peak at > (2500/.0466)^.5=~232 > seconds. I suppose I could then compare the activation time to the > time for max RHR and get a percent before or after for the different > growth rates and max RHRs. > thanks, > Brad > > -----Original Message----- > From: Roland Huggins [mailto:[email protected]] > Sent: Thursday, October 03, 2013 10:57 AM > To: [email protected] > Subject: Re: Spacing Rules > > I was simply trying to make the reference to time more than just how > many seconds have passed and tie it to the level of hazard presented > by the fire by using the same point on the different fire curves. > > Roland > > > Roland Huggins, PE - VP Engineering > American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives > Dallas, TX > http://www.firesprinkler.org > > > > > > On Oct 3, 2013, at 5:54 AM, Brad Casterline <[email protected]> > wrote: > > > Dang Roland this opens up a whole new can of curiosity for me. > > Figuring out exactly what you mean will give me something to do the > > next couple-three lunch breaks. I usually check out the FDS-SMV > > discussions > but > > for some dumba$$ reason the NIST site has been down since Tuesday (smh). > > > > Brad > > **************** > > ..... A more meaningful reference for activation is in regard to the > > same RHR point for the different fire curves...... > > > > ...... > > Roland > > > > Roland Huggins, PE - VP Engineering > > American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives > > Dallas, TX > > http://www.firesprinkler.org > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
