We have the same issues here in Canada. We have used a carved channel in the foam insulation with minimum 1" air space around the pipe complete with grates at top and bottom with the CYA letter for the required heating. The other method we have used is to have the general contractor frame down the entire ceiling with 2x4 for recessed heads and 2x6 for concealed heads. This way you ensure you have adequate insulation above your pipe with no reductions. Our contractors are often stuck on batt insulation in which case they may be required to provide gyproc directly attached to the joists and then do the frame down with another layer of gyproc.
Sheila Gabler HPF Engineering Ltd. 101-1402 McGill Road Kamloops, BC, V2C 1L3 Ph: (250) 828-7992 Fax:(250) 828-0984 email: [email protected] ----- Original Message ----- From: "Thom" <[email protected]> To: <[email protected]> Sent: Friday, June 24, 2011 8:52 AM Subject: RE: As Ron say's "Heat Loss" We have handled this similar to what you propose with two exceptions. To promote "Positive" heating of the branch line, we had a 6x12 open louver installed at the low end of the "chase" (joist space) and at the high end. Then convection did the rest. We also sent a CYA letter stating that our design required that the space heating maintain a minimum of 60'F as opposed to the 40'F allowed by NFPA. We made sure to state that freezing could occur if there was any failure of the heating system during the heating season. Also due to another issue that has occurred with this type of installation, require the GC to insure that there are no ducts or exhaust duct (bathroom exhaust or kitchen hood)allowed in this or the adjacent joist space. (Those little flappy back-draft dampers tend to stick open allowing cold air back into the unit, if it's near your pipe it will freeze.) Lastly, is there a reason you're not looking at HSW heads "Down the slope" spray pattern? We have used these in the past to avoid exactly what your doing. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ron Greenman Sent: Friday, June 24, 2011 8:24 AM To: [email protected] Subject: Re: The question becomes what is the heat loss through the insulation in relation to the heat gain in the room. Presume no insulation and the roof is still a barrier and still has a R value. So if my heat loss is X.zero and my input (at the same point) is equal to (1) X.zero or increased to (2) X.something and my starting temperature was 70F then I will maintain (scenario (1)) or increase (scenario 2)) the temperature at that point in the room. An ice cave is a shelter because it protects your body from the wind which conducts heat away from your heat engine (metabolism) and confines the air space around you and insulates that space from rapid heat transfer to the larger environment, hence lessening the your radiant heat loss. It's all about the thermal balance. Now back to the Ashram. On Fri, Jun 24, 2011 at 7:09 AM, Todd Williams <[email protected]> wrote: > I am working on a small mixed-use building with commercial space on the > first floor and an apartment with loft above. Part of the apartment has a > cathedral ceiling, which needs to have sprinklers on the slope. No other > options. The roof is framed with 2x10s and they plan to use a spray in foam > insulation the entire depth of the joists. My thought was if they took one > joist bay and only put 5" of insulation and create a space to run the pipe. > Would that be sufficient to prevent pipe from freezing? I also thought about > putting a small grate at the bottom and top of the channel to allow heat to > flow into the space. Has anyone done anything like that before? Thoughts on > weather it would work? Not a lot of options and I don't want to go with an > antifreeze system > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, CT > 860.535.2080 > www.fpdc.com > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > -- 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 They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
