Looped system with non Looped sprinkler system

[ME.EnGR]

Good day, im a beginner in fire protection design. i know how to hand calc a simple branched fire protection system, i have a question regrading this new design that i was working on. For me its my first challenge as designer.You can look at the primary design that i have made (with architects direction) i have attached a picture of it, my questions will be how can i calculate a system with looped and not looped branches?, where is the most remote area that i should consider ( you can see a 3 rectangular shape 1500sq.ft in area that im considering to get the most demand). Thank you. Lastly since the building is a Mercantile classification i designed it Ordinary Hazard 1 where the are of protection of a sprinkler is 130sq.ft x 0.15gpm/ sq.ft = 19.5 gpm then if you tried to find the pressure in the most remote sprinkler using the required flow of it that, (19.5/8)^2 = 5.94psi (its below the 7psi minimum of NFPA 13). Im thinking of using 10psi for the most remote sprinkler to be safe, is it better to have 10psi at the very end sprinkler or just 7 psi?. Again thank you for helping. God bless.

 

[MatthewJWillis]

I don't believe your question/s can be answered here. There are far too many variables.

It seems you have the basics down somewhat. I would recommend a thorough review of the calculation procedures in NFPA 13.

At a glance, it seems your systems are a grid?? Also at first glance, the sizes of your remote areas are incorrect. Hint, they should extend from the center line between the 2 sprinklers at opposite ends.

R/
Matt

 

[TravisMack]

As Matt said, you have too many variables. You need direct supervision of your project as this is off.
1 - Mercantile is OH Grp II, not Grp I.
2 - Choose a 5.6K sprinkler instead of K8 - however, when you apply the proper density, a K8 may be better.
3 - based on the way your remote areas are laid out, it seems that you need further direction on proper remote area selection and sizing.
4 - You do NOT want to do a hand calc of a grid. It will take you days to complete.

I mean this to be constructive criticism and not negative. Please seek out a proper mentor for fire sprinkler / fire protection system design. An architect is not qualified to guide you in your fire sprinkler system career.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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