Charles, Devils Advocate. What if the distance from the holes in the base to the ceiling is the same as from the holes to the insulation layer? Wouldn't that be the same thing? Heads mounted in a ceiling with an isolation "tent" at the joist top level form a channel but keep the heat going from the holes getting into the attic (the thermal barrier the insulation creates keeps the joist bay the heads are in within the "inside" of the heated area) effectively creating a situation exactly like the channel formed by the false beam.
Rocci, Two separate issues. Deflector distance is a distribution issue. The holes in the can of the concealed sprinkler are an activation issue. The airflow through the holes, as Charles pointed out, can't be impeded as the hot won't flow past the fusible link, but rather create a stagnant cool barrier will form in the can and the heat from the fire will never impinge sufficiently on the link (at least within the time frame required by the listing) to activate. In short, the dimensions you addressed have to do with what's going on in the room (and there may be some caveats about how deep the beam can be), and the other issue has to do with airflow in the channel. I think the Tyco guy may have equivocated because he didn't have a definitive statement to back up his comment. They are careful for good reason. In an informal discussion once with a senior guy from Rhode Island over a new product with a great listing, I asked if the verbiage could be construed to allow a certain application that was not specifically addressed in the listing but worked logically, he said no. When I asked why he said, and was this forthcoming because he's a friend and knew I wouldn't do anything to harm him if he was completely honest, that my application as stated would probably be OK and work fine but the product was new and hadn't been tested under the conditions/scenario I'd described so liability issues required that the answer be no until more data was available. A perfectly good rationale. On Fri, Oct 9, 2015 at 9:13 AM, Charles Thurston <[email protected]> wrote: > Hello Rocci, > > A false beam installed below the solid ceiling will stop the airflow that > would normally go into the attic space during a fire. That airflow is > critical for the concealed head to operate. > > Friday, October 9, 2015, 11:52:13 AM, you wrote: > > > Does anyone have any knowledge on installing concealed pendent > sprinklers in > > false beams? The Reliable cut sheet (bulletin 006 Rev I) for RFC43 says > “top > > of deflector to ceiling installed in beams ½” to 1”. Now the residential > > sprinkler design guide (bulletin 140 Rev K) specifically says “RFC > > concealed sprinklers cannot be installed in structural or false beams > that > > impede the flow of air through the vent holes into the space above.” I’m > > not exactly sure what would impede the flow??? > > > > > > The Tyco cut sheet only says the deflector to ceiling for concealed > heads > > installed in beams 7/8” to 1 1/8” below bottom of beam. When I called > Tyco > > all the guy said was, from the way we understand it you can install them > in > > beams and just follow NFPA sprinkler deflector criteria…….he didn’t sound > > very convincing and I’m just all around confused, I do very little > > residential project so I’m not as familiar and up to date on all things > > residential. Any information would be helpful. > > > > > > Thank You > > > > > > Rocci Cetani III, CET > > > Lead Designer > > > Water-Based Fire Protections Systems Layout, Nicet Level III > > > > > > Northern California Fire Protection Services Inc. > > > 16840 Joleen Way Bldg. A > > > Morgan Hill, CA 93037 > > > P-(408) 776-1580 EXT.111 > > > F-(408) 776-1590 > > > > > > > > > [email protected] > > > www.norcalfire.com <http://www.norcalfire.com/> > > > > > > CONFIDENTIALITY NOTICE: This message and any document accompanying it may > > contain confidential information > > > belonging to the sender. The information is intended only for the use of > > individual or entity named above. If you are not the intended recipient, > or > > the employee or agent responsible to deliver this message to the intended > > recipient, you are hereby notified that any disclosure, copying or > taking of > > any action in reliance on the contents of this information is strictly > > prohibited. If you have received this transmission in error, please > > immediately notify us by telephone to arrange for return of the > documents. > > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > -- > Best regards, > Charles mailto:[email protected] > > _______________________________________________ > 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
