Ken, So you would installed the ESFR sprinkler directly under the center point of the round duct. (i.e. the 84" diameter duct, the sprinkler would be at 42" from the edge at the listed distance below.) Would a round duct collect enough head to set this off???
Thanks, Gregg Fontes Cen-Cal Fire Systems, Inc. 209-334-9119 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Parsley Consulting Sent: Thursday, September 03, 2015 6:46 AM To: [email protected] Subject: Re: Larger circular duct obstructions Greg, A couple of thoughts come to mind for me. First, I would regard the large circular duct as similar to unobstructed construction. The location of the deflector of the sprinklers below the duct would have to be as called out in 8.12.4.1. So, for those purposes the position below the duct would be driven by the k-factor you're using. Second, the use of an ESFR system to protect LH/OH occupancies is allowed by 12.6.7.1, provided that the original design was per the criteria in chapters 12 through 20. I don't think the manufacturers are going to stand behind designing ESFR's to meet obstruction rules for standard spray sprinklers. To my way of thinking the continuous obstruction rules of 8.12.5.3.1 would still be applicable. I don't agree that it would be possible to eliminate the concern over obstructions less than 48" wide, as items (3) and (4) of that section suggest 24" is the cutoff width. I don't know if that's correct, however those are my initial thoughts. *Ken Wagoner, SET *Parsley Consulting*** *350 West 9th Avenue, Suite 206 *Escondido, California 92025 *****Phone 760-745-6181* Visit our website <http://www.parsleyconsulting.com/> *** On 09/02/2015 2:18 PM, Gregg Fontes wrote: > Looking at a building that has ESFR fire sprinkler protection. Half > is being used as open office area. They are installing circular ducts > from 32" to 84" diameter with the top of the duct approximately 36" > below the ESFR deflector (right below the roof trusses). In reading > 8.12.5.3 2013 edition, in most cases if not all, Table 8.12.5.1.1 > cannot be met, so sprinklers will need to be installed under the > ducts. With the duct being 32" to 84" diameter, where would the fire > sprinkler be placed? Per NFPA 13 is a flat barrier required to be > installed under the circular duct? FM give you a guideline, but 13 > does not. Owner does not want the ESFR sprinklers change out, so > again where would you place the sprinkler and/or is a flat barrier > required by NFPA 13? (With a flat obstruction you can either be under > it or within so many inches of the end, but a huge diameter > obstruction, is it the edge, center ,etc.?) > > Second thought, since this is no longer a storage application, can you > apply the standard spray sprinkler obstruction rules? (This still > does not state where to install the sprinkler below the obstruction, > but you could eliminate the obstruction less than 48".) > > Thanks, > Gregg Fontes > Cen-Cal Fire Systems, Inc. > 209-334-9119 > > _______________________________________________ > 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-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
