In Section 188.8.131.52(3) of NFPA 13-2019 Edition, discusses that rooms or compartments 800 sqft or less (small rooms) should be calculated based on delivering 0.10 gpm/sqft over the room or the compartment by using the area of the room divided by the number of sprinklers in the room.
I believe I've overcalculated remote areas in the past.
My project now is an apartment building designed according to NFPA 13. Using residential type sprinklers with non-sprinklered combustible concealed spaces. According to Section 184.108.40.206 I need to calculate a minimum of eight sprinklers.
In the past I've calculated the eight sprinklers using the actual spacing based on the S x L rules with a 0.10 gpm/sqft density.
One room example - room dimension of 24 x 12 is 288 sqft. Two sprinklers spaced in a compartment 8'-0" off one wall and 6'-0" from adjacent wall. Using the S x L rule: 16' x 12' = 192 sqft x 0.10 gpm/sqft = 19.2 gpm each.
Or, according to Section 220.127.116.11 (3), would I divide the room size 288 sqft by 2 sprinklers, which is 144 sqft per sprinkler, regardless of the actual sprinkler distance from the walls? This second scenario would result in a 14.4 gpm required flow.
Or, was the code option (3) assuming the sprinklers are evenly centered within the compartment.
Thanks in advance for your input and clarification.
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