shape of the design area in the case of storage

[yassinemzili]

I have a simple question. For example if I'm in the case of designing automatic sprinkler for storage and work with the table 12.2.2.2.1(a)NFPA13(ed 2002) how can I detemine the shape of the design area and number of prinklers in each branch lines?

My suggestion is to apply 14.4.4.1.1 NFPA13(ed 2002) and calculat the number of sprinkler in branch lines by this formula:
1.2*sqrt(design area)/(distance between sprinklers in the same branch)
am I right?

 

[sac32079]

is this a ESFR calc?

 

[sac32079]

*an*

 

[yassinemzili]

no it's a standard spray sprinkler

 

[TravisMack]

I was taught that the # of sprinklers method is only good if everything is uniform. You must always meet the length requirements. So, if you have a 2000 sq ft design area, the length along the branch line shall be a minimum of 1.2(2000^.5) or 53.67'.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[SuperiorFire]

Have a look in the Annex of the NFPA #13

Figure A.22.4.4 should point you in the right direction.

Like Travis says, though, you might have to calculate 'extra' heads if heads are spaced non-uniform.

Superior Fire Protection Systems
Protectiong Lives and Property since 1986.

Vancouver, British Columbia

http://www.superiorfireprotection.ca

 

[yassinemzili]

In the case of large drop and ESFR sprinkler system disigned for storage table 14.3.1(a)and 14.4.1 from NFPA13 (ed 2007), how can I find the design area ?
I look in the NFPA 13 and didn't find the design area for tha case.

 

[SuperiorFire]

14.4.3

Assuming your system is a grid, you will calculate 4 sprinklers on each of 3 branch lines, for a total of 12 sprinklers. The shape will thus be a rectangle.



Superior Fire Protection Systems
Protectiong Lives and Property since 1986.

Vancouver, British Columbia

http://www.superiorfireprotection.ca

 

[SuperiorFire]

Also read 22.4.4.3 in NFPA 13. This should be pretty definitive for you.

Superior Fire Protection Systems
Protectiong Lives and Property since 1986.

Vancouver, British Columbia

http://www.superiorfireprotection.ca

 

[yassinemzili]

So if i understant what's in the 22.4.4.3 NFPA13, the design area should be at least 960sqft

 

[SuperiorFire]

And at least 12 Sprinklers. Unless superseded by another line of code. What is the storage application?

Superior Fire Protection Systems
Protectiong Lives and Property since 1986.

Vancouver, British Columbia

http://www.superiorfireprotection.ca

 

[yassinemzili]

it's to stor wood furniturs( chairs,cupboard,desk...) but I don't know how are they stored