Web Exclusive Feature! Fire Protection for Glazed Windows
"Exposure Protection" and "Fire Resistive Rating" are two completely different terms that are often confused when it comes to the application of automatic fire sprinklers. NFPA standards such as 101, Life Safety Code; 80A, Protection of Buildings from Exterior Fire; and 13, Installation of Sprinkler Systems, all reference protection criteria for exposure protection. None of these, however, state that the closely spaced sprinklers required for exposure protection establish a fire rating as required by the building code.
Currently, there is also confusion between the term, "Listed Window Sprinklers," as advertised by some manufacturers. If you were to look in the Underwriters Laboratories (UL) Fire Protection Equipment Listing Directory, you will find a listing category titled: "Sprinklers, Outside (VOKR)." Under this heading, you will find an explanation stating, in part: "These sprinklers are non-automatic and are intended for protection of windows, walls and roofs against exposure fires." These nozzles (none in this category have operating elements) are intended for use with deluge systems to provide exposure protection and will not provide a fire resistive rating.