For all practical purposes the air decompresses evenly throughout the system so trip time will be essentially the same no matter where the device is located as long as it's not on a line less than 2". So picture the difference with air decompressing through a 2" hole and a 1/2" hole anywhere. 15 open heads faster than 1 open head. The rub comes in with transit time: as soon as water hits the exhauster it closes down so if the exhauster is at the riser you get a fast trip but you still need to push the remaining compressing air being displaced by the encroaching water out the open heads. With the exhauster further down the line you still have the extra 15"heads" open for a longer time. But since transit time once the DPV valve has tripped is pretty quick this "extra" may be incidental. Maybe someone should make an experiment. Oh, wait.... No more exhausters to install so purely an academic endeavor. Probably could get a grant from somewhere to study how they worked when we used them.
On Thu, May 22, 2014 at 7:17 AM, Roland Huggins <[email protected]>wrote: > But you have a shorter duration so it may be a wash. > > > Roland Huggins, PE - VP Engineering > American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives > Dallas, TX > http://www.firesprinkler.org > > > > > > On May 22, 2014, at 6:05 AM, Jamie Seidl <[email protected]> wrote: > > > It may be difficult, but would it be possible to install a ITC manifold > per > > 2007 NFPA 13 7.2.3.6.1 (A7.2.3.7)? Maybe that could help exhaust more > air > > out of the ITC and help with the transit time. > > Jamie Seidl > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.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) A problem well stated is a problem half solved. -Charles F. Kettering, inventor and engineer (1876-1958) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
