If you need to protect above the duct and get quicker detection then you could use vertical sidewall heads on candle sticks up the side of duct and stagger space.
Russell Gregory Christchurch New Zealand From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of Larry Keeping Sent: Thursday, 15 September 2016 3:32 PM To: email@example.com Subject: RE: Noncombustible concealed space I would offer two points for your consideration: 1. There was an old formal interpretation that advised that deletion of sprinklers above a duct was a question for the AHJ, who could access all of the circumstances. 2. Sprinklers above open grid ceilings need to be in compliance with Section 8.15.14. Larry Keeping From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of Tim Stone Sent: September-14-16 10:04 PM To: firstname.lastname@example.org Subject: Noncombustible concealed space I have an interesting situation. Steel and concrete School building. A Corridor runs down the middle on each floor about 8' wide, W12 steel I-Beams forming the side at the floor deck above, (About 12'-0 Floor to Bottom of deck). There is a large duct running the length of the Corridor about 7'-6 wide x 24" tall. This leaves a gap of about 3" on each side between duct and sheetrock partitions. The top of the duct is about 11" below the steel Q-Deck above. An open metal grid ceiling system is installed 12" - 16" below the duct. We are installing upright heads 1"-4" below the duct allowing the water to spray down through the open grid ceiling. The question is, do I need to install heads above the duct? There will be no way to service or replace these heads and if installed between the duct and the wall, the head will not meet the minimum 4" off the wall. Referencing 2010 ed. 18.104.22.168.1, concealed spaces, I believe I am following the intent. Thank you in advance. Regards, G. Tim Stone G. Tim Stone Consulting, LLC NICET Level III Engineering Technician Fire Protection Sprinkler Design and Consulting Services 117 Old Stage Rd. - Essex Jct., VT. 05452 CELL: (802) 373-0638 TEL: (802) 434-2968 Fax: (802) 434-4343 <mailto:tston...@comcast.net> tston...@comcast.net
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