"Area of Sprinkler Operation" definition 1

[mizunogolf]

I am new to NFPA and I am trying to determine spray density. I have yet to hear a definition for basing a "area of sprinkler operation" - NFPA 13 - Figure 11.2.3.1.1. I am trying to size for a 37,000 ft^2 building and all I hear from people are "rules of thumb". I fall in Ordinary hazard 2 and I am continually told 1500 ft^2 is fine, just as long as I am on the line somewhere. There is a lot of difference from 1500 vs 4000 ft^2 in terms of gpm required.

All three floors are open so compartmentalizing would be a wag.

Any helpful hints???

 

[cdafd]

seek professional help

is this an office, store, flammable liquid storage room



nfpa 13 2002 edition
check
11.2.3.1.8

11.2.3.2.1.2

11.2.3.2.3

11.2.3.2.3.2


They are correct in stating you can pick any where along the line as long as you stay above the line

 

[cdafd]

Note: The Design density is determined from the water discharged through the sprinklers divided by the area covered by the spray. The Area of operation is the area over which the sprinklers will discharge.

http://www.sharkspol.cz/eng/sprinklery-norma.html#5

 

[TravisMack]

I am assuming you are using control mode, standard spray sprinklers. You look to NFPA 13 for your design area. IF the criteria is OH2, then you calculate a 1500 sq ft design area. It doesn't matter if the building is 1 story or 50 stories. You are only calculating have a fire in a single area. You calculate 1500 sq ft. There are some modifications you can make if applicable, but that is your base.

Truthfully though, you need to have someone provide more guidance than can be offered through an internet forum. This is a great place to get SUGGESTIONS, but ultimately, you are the one responsible for the layout and need to understand how and why the system is to be designed a certain way.

Good luck!



Travis Mack
MFP Design, LLC

 

[stookeyfpe]

Adding to your terminology:

The most hydraulically remote 1,500 square foot area is calculated.

Follow CDAs and Travis's comments and seek professional design assistance.