When doing the hydraulic calculations for an open space (having only upright sorinklers), we calculate the No. of sprinklers based on the Max. protection area and the Area of coverage (ex: 1,500 ft2 / 130 = 11.5 = 12 sprinklers). In case we have the same area, same hazard, but the area is not an open space, it has a false ceiling (open office space for example) and we have upright and pendent sprinklers.
1-The 12 sprinklers shall be doubled? (considering 24 sprinklers to cover the area above and below false ceiling?)
2-The 12 sprinklers will be considered to cover above false ceiling OR below false ceiling since fire cannot happen simultaneously?
3-any other consideration?