Selection of Sprinkler Zones

[C Singh]

Good Morning Everyone, Just getting back into sprinkler design after some time, I have an Ordinary group II warehouse (25000 sq ft) with 1st and 2nd floor offices at the front of the building (1350 Sq ft).
Would the office have to be on a separate zone? Where can I read more about this?

Your help is greatly appreciated. Thank you!

 

[LCREP]

NFPA 13 has the requirements, one riser is ok. I have questions on the ord haz 2 on the warehouse, what is the product commodity classification, storage configuration i.e. racks, on floor, height of storage and ceiling height?

 

[C Singh]

Thanks for your reply LCREP. It is a warehouse divided into bays where they will be customizing shipping containers to use as site offices etc. not a warehouse for storage. The height of the ceiling is approx 116 feet. Thanks for your time and help.

 

[TravisMack]

If they are building things inside the shipping containers, you may be looking at a shielded commodity and may need to think of it like modular housing or something which is more of an EH2 criteria.

Anyway, with regard to the question, a single system can protect up to 52k sq ft per NFPA 13, but only 40k sq ft of EH and storage criteria. So, you can have 40k sq ft of storage and 12k sq ft of office and still have a single system, but 45k sq ft of storage is going to be 2 systems. Now, if you are under FM criteria, the system area limitation has been removed. You are only limited by hydraulic calculations and practical installations. Sure, you may be able to do a single system of 1M sq ft, but 12" mains and 4" branch lines would not be very cost effective.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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[C Singh]

TravisMack, this info is a big help to me. Thank you very much!

Speak soon
Curtis

 

[LCREP]

As Travis said see below NFPA 13, 2013 ED. More like .40/2500, but with a 116' high ceiling I wonder if even that high of a density will do much.


5.4.2* Extra Hazard (Group 2). Extra hazard (Group 2) occupancies shall be defined as occupancies or portions of other occupancies with moderate to substantial amounts of flammable or combustible liquids or occupancies where shielding of combustibles is extensive.

 

[TravisMack]

I was hoping that 116' ceiling was a typo and was meant to be a 16' ceiling. 116' ceiling in a warehouse seems crazy. Assuming these boxes are at most 20' tall, I can't see a sprinkler being effective 86' above the fire. I believe that 13 requires you to design for a storage hazard to within 10' of the roof.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

https://www.facebook.com/pages/MFP-Design-LLC/92218417692

 

[C Singh]

You guys are good! It is 16' not 116'. Thank you both for your help! Merry Christmas!