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EN 12845 / NFPA 13

Sprinkler count for rectangular room

Number of sprinklers needed for a rectangular room given hazard class and coverage area.

Divides the room area by the maximum coverage area per sprinkler for the selected hazard class, then rounds up. Real layout may need more heads near walls and obstructions.

12 = OH; 9 = HHP; 21 = LH

Result
Room area
96
Sprinklers required
8
Approx. square spacing
3.46 m

Formula: N = ceil(L × W / A_max)

Reference: EN 12845 / NFPA 13

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