Art, Just to be Devil's Advocate--How long is too long? I keep hearing that song but no definition of time. Since by the new rules I have 60 seconds to get water to the most hydraulically remote single head is 60 seconds or less too long? Since using QR heads instead of residential heads in 13 residential occupancies is an option I can have a dry system by code. I can use all of Ken's rules also. The question remaining then is: How long is too long for me to feel that my design is inadequate? Now if we feel uncomfortable about not having instant water when the head fuses then we shouldn't do it. That brings up another question though. Since a dry head does not have the mass and conductive properties of the water impinging on it like a wet head would is there an appreciable reduction in response time for a dry head compared to a wet head with fires of equivalent heat release rates? If there is how much does this counterbalance the increased transit time (0 seconds for wet--up to 60 seconds for dry).
On Mon, Mar 30, 2009 at 1:17 PM, Arthur Tiroly <[email protected]> wrote: > Ken, > If the hallway is part of that dry system it is a larger room. Would you > calculate 7 heads in the hall? It still takes too long for the 1st sprinkler > operating to get water for a QR residential occupancy for life safety. > > Arthur Tiroly > ATCO Fire Protection Design > Tiroly and Associates > 3300 King Ave > Cleveland, OH 44114 > 216-621-8899 > 216-570-7030 cell > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > ParsleyConsulting > Sent: Monday, March 30, 2009 2:20 PM > To: [email protected] > Subject: Re: RESIDENTIAL OCCOPANCY DRY SYSTEM > > Thom, > > Does that mean that in a hotel protected by an NFPA-13 compliant system > that I could design the system using only quick-response > (non-residential) sprinklers, and thus change the minimum number of > sprinklers flowing in the calculations? > > My thinking is that the guest room would certainly be classed as light > hazard, and as long as self-closing doors were present, I would be > allowed to use the room design method. Based on that, I could provide > calculations for only those sprinklers in the room flowing, and because > it is a "small room" as defined by 3.3.15, I would only have to provide > the density of water times the area of the room divided by the number of > sprinklers in the room for minimum flow from each sprinkler, per > 8.6.2.1.2. That would certainly allow me to use smaller orifice > sprinklers in the room, and reduce the total water flowing in the room. > > Of course, I'd also have provide a corridor calculation based on five > sprinklers flowing, per 11.2.3.3.6, but using SxL I could also 4.2K > sprinklers in the corridor, reducing the water flowing and still keeping > the density provided at the required level for light hazard. > > Interesting possibilities. > -- > > PARSLEY CONSULTING > > Ken Wagoner, SET > > 760.745.6181 voice > > 760.745.0537 fax > > [email protected] <mailto:[email protected]> e-mail > > www.ParsleyConsulting.com <http://www.ParsleyConsulting.com> website > > > Thom McMahon wrote: >> Just as a follow up: >> >> 8.4.5 Residential Sprinklers. >> 8.4.5.1* Residential sprinklers shall be permitted in dwelling >> units and their adjoining corridors, provided they are installed >> in conformance with their listing. >> 8.4.5.2 Residential sprinklers shall be used only in wet systems >> unless specifically listed for use in dry systems or preaction systems. >> >> "Permitted" not required. >> >> Thom McMahon, SET >> Firetech, Inc. >> 2560 Copper Ridge Dr >> P.O. Box 882136 >> Steamboat Springs, CO 80488 >> Tel: 970-879-7952 >> Fax: 970-879-7926 >> >> >> >> >> _______________________________________________ >> Sprinklerforum mailing list >> http://lists.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 > http://lists.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 > http://lists.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 at home.... _______________________________________________ Sprinklerforum mailing list http://lists.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)
