Dear Forum,
I would appreciate feedback on the technical (or moral) correctness of the following scenario: NFPA 13 (2010 or 2013), Light Hazard, Ceiling smooth and flat at 10'-0" AFF. Sprinklers= QR, EC, 200F, K=11.2 at 20' x 20'. Choose .07/3000 for starting point from L.H. curve. Apply Q.R. Reduction-- 3000 x .6 = 1800 ft^2. Length of operating area = 1.2 x SQRT(1800) = 50.91 ft., / 20 = 3 hds/line. 1800/400= 6 hds operating. Q=400 x .07 = 28 GPM. P=(28/11.2)^2 = 6.25 PSI raise to EHP= 7 PSI. Since (5) is the minimum number of operating heads for Density/Area, is it OK to 'choose' the density based on 3000 ft^2, or would it be more righteous to 'use' the density based on 5 x 400 = 2000 ft^2, .09, then reduce the operating area to 2000 x .6 = 1200 ft^2? thanks, Brad Casterline, NICET IV Fire Protection Division FSC, Inc. P: 913-722-3473 [email protected] www.fsc-inc.com Engineering Solutions for the Built Environment _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
