Raminta Raskauskaite

Hydraulic calculation ceiling and suspended ceiling sprinklers

Discussion created by Raminta Raskauskaite on Mar 12, 2018
Latest reply on Mar 12, 2018 by nocivus


I have HC-3 sprinkler system for production (no storage) room. K-160 pendant sprinklers 12mm/min@340 m² will be used. There will be two levels of sprinklers one under the ceiling and one in solid suspended ceilings (the same type of sprinklers will be used for both levels due to client req.). Distance between suspended ceiling and ceiling ~4.4 m. They will be controlled with one signal valve, but each level has separate feed mains (floor area ~7400 m²). It is hydraulically calculated system.

1) Shall I calculate hydraulically both levels of sprinklers together in 340 m² area?

2) Shall I evaluate each level separately?

3) Or is hydraulically most unfavorable area under ceiling (highest sprinkler level) and hydraulically most favorable area is in suspended ceilings level?

Is it described in NFPA 13 and FM Global req.? Because for me it's a question how to evaluate sprinklers hydraulically when I do have suspended ceilings with sprinklers.