Me too until the 2010 language. Now it appears a single row of in-racks can be used to make up for the excess ceiling clearance requirements for Chapters 16 and 17. With this set of in-racks in place the racks can be calculated at the actual storage height rather than the theoretical Ceiling - 20 Chapter 16 (or Ceiling - 10 Chapter 17) height required by 13-2007.
The way I read this is the "ceiling clearance in-rack" flow does not have to be added to ceiling flow if the commodity class and "assumed acceptable clearance" would not otherwise require in-racks. When the actual storage height would necessitate the in-racks, then the in-racks could serve double duty as the required in-racks as well as the "ceiling clearance in-racks". In this case the in-rack flow is added. All this being stated, my concern is whether this approach is OK for the Chapter 17 plastics. Bill Brooks William N. Brooks, P.E. Brooks Fire Protection Engineering Inc. 372 Wilett Drive Severna Park, MD 21146-1904 410-544-3620 410-544-3032 FAX 412-400-6528 Cell -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ronl.Fletcher Sent: Thursday, February 17, 2011 8:36 AM To: [email protected] Subject: RE: Rack Storage Sanity Check (13-2010) Bill, Have you looked at 12.1.3.4.1 and A12.1.3.4.1? I have always been under the assumption that 20 feet clear above the top of storage was the max. Ron Fletcher Aero Automatic Phoenix, AZ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bill Brooks Sent: Wednesday, February 16, 2011 6:42 PM To: [email protected] Subject: Rack Storage Sanity Check (13-2010) Figure 17.2.1.2.1(d) shows my situation - Group A plastics, four tier double row racks, but 23 (twenty three) ft ceiling clearance. I'm assuming one level of in-racks below the top tier is necessary based on 12.1.3.4.4, with in-racks spaced at 5 ft based on bottom right Figure 17.2.1.2.1(d). If this is an acceptable arrangement it looks like the Group A plastic protection could be less demanding than encapsulated Class IV for this configuration if you discount the differences in the spacing of the in-racks for each case. Is this because the encapsulated Class IV commodities can be a greater fire hazard than the cartoned (or exposed unexpanded) plastics? Am I missing something really big with respect to ceiling clearance and Group A plastics? I know you just can't do ESFR when ceilings are too high, but are Group A plastics similar? Bill Brooks William N. Brooks, P.E. Brooks Fire Protection Engineering Inc. 372 Wilett Drive Severna Park, MD 21146-1904 410-544-3620 410-544-3032 FAX 412-400-6528 Cell _______________________________________________ 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)
