Allan, If you have a copy of the 2007 flavor of NFPA 13, look at the new section 11.1.5.2 (3). As long as the higher hazard areas are enclosed & no greater than 400 sf and separated from other higher hazard areas, you're allowed to use the duration and hose allowance for the lower hazard. Nice addition.
Ed Kramer Littleton, CO >Forum, > >I think variations of this topic have been mentioned before but I >must apologize for not paying attention. This is about tank sizing. > >There is an example in the 13 appendix for determining the design >area when the higher hazard type is in a room with walls good for at >least the water duration for the higher hazard type. For that >condition the design area for the lower hazard type is used to >encompass both spaces. The appropriate application density for the >larger hazard is used for the larger hazard area and appropriate >application density for the lesser hazard is used for the balance of >the total design area in the lower hazard space that is outside the >walls of the higher hazard space. Now you have probably guessed where >this question is going. Since the total Design Area to be used is >that of the lesser hazard, does that also mean the Design Duration >for the lesser hazard applies to both hazard areas? The question >seems silly here but there is a glimmer of possibility in the >language used in the NFPA 13. This would mean 30 minutes for each >space application where the hazards are LH and OH2. My own thinking >would be 60 minutes for the OH2 portion and 30 minutes for the LH >portion when the required durations are 60 and 30. When space and >budget are tight the difference is significant when it boils down to >13 according to Hoyle versus opinion and there is this BlueBird sized >shape parked somewhere in the building. > >Thanks, >Allan Seidel >St. Louis, MO _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum
