Cleanroom Sprinkler Systems

Early cleanrooms were sprinklered using a pipe schedule system. While these were acceptable in the past, they are not being recognized for new installations since NFPA 13 was revised in 1991. In the 1991 revision, they limit the use of schedule systems to 5,000 sq. ft. NFPA 318 Standard 

There are also other sprinkler developments that may not be as well suited for cleanrooms. These would be items specifically designed to reduce the cost of sprinkler systems. Two items are specialty pipe and extended discharge head. 

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Dry Pipe. The dry pipe systems are only desirable where adequate heat is not provided. This wouldn t be used for a cleanroom installation. It might be used for outside storage rooms or unheated areas of exposing building. It is slower than the wet pipe or preaction system and could allow a fire to get ahead of the sprinkler system. It is not acceptable for protection of flammable liquids. 

Approved quick response sprinklers shall be utilized for sprinkler installations within downflow airstreams in cleanrooms and clean zones (NFPA 318 2-1.2.2). The use of quick-response sprinklers is intended to overcome some of the tendency for the sprinkler element to be cooled by the downward airflow, thus, causing the sprinkler system to respond to a smaller size fire more quickly than a system utilizing conventional sprinklers. 

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