Ordinary and High temperature sprinklers

In NFPA 13, there are conditions where the designer can choose Ordinary or High temperature sprinklers. In each case some advantages are afforded. In this text, we examine some parts of NFPA 13 that are related to this subject. Advantages of High Temperature Sprinklers: 1) A 25% reduction of sprinkler operation area (but not less than 2000 ft²) in Extra Hazard Occupancies that are protected by Standard Spray Sprinklers. [Chapter 11, NFPA13-2016 Edition] As mentioned in Figure 1, If High temperature CMDA sprinklers are used for design, the minimum estimated flow rate will be: 0.3 gpm/ft.² x 2000 ft.²= 600 gpm With ordinary temperature sprinklers: 0.3 gpm/ft.² x 2500 ft.²= 750 gpm

2) Reduction of the area of sprinkler operation (from 3000 ft² to 2000 ft²) for indoor storage of idle wood pallets, that are protected by CMDA sprinklers, on floor storage of pallets (Maximum storage height= 6ft. and Maximum ceiling height= 20ft.). [Chapter 12, NFPA13-2016 Edition] 3) Lesser design density for Palletized, Solid Piled, Bin Box, and Shelf storage of Class I through IV commodity that protected by CMDA Sprinklers. [Chapter 14, NFPA13-2016 Edition] Example: Assume Solid piled storage of Non-encapsulated Class I commodity, at a storage at a height of 20ft, If High temperature CMDA sprinklers use for this design, in accordance with Figure 2, the minimum estimated flow rate will be: 0.152 gpm/ft.² x 2000 ft.²= 304 gpm

With Ordinary temperature CMDA sprinklers (Figure 3): 0.206 gpm/ft.² x 2000 ft.²= 412 gpm