March 21, 2016 Sidewall Sprinkler Above Light Cove "An architect wants to use a light cove in corridors of an NFPA 13R senior apartment project. The sidewall deflector is 12 in. down from the ceiling and the body and escutcheon is even with the front of the light cove. The width of the light cove is less than 8 in. and the bottom of the cove is approximately 30 in. from the ceiling. Do sidewall sprinklers located 6 in. from a wall above the light cove meet the intent of NFPA 13R?" We have reviewed NFPA 13R, 2010 edition that you indicated as the applicable standard. Our informal interpretation is that this arrangement should be allowed. If the area above the light cove could be converted to a soffit, this arrangement would comply with section 6.4.6.3.6.2. If modifications to the current arrangement are not possible, this should be permissible if allowed by the AHJ. The NFPA 13R standard cannot address every possible sprinkler application, but there are clues that this arrangement should be allowed. The basis for evaluating such equivalencies, although not stated in NFPA 13R is stated in NFPA 13, Section 8.1.1(3), is that sprinklers are located to provide satisfactory performance with respect to activation time and distribution. Lets first look at distribution. Since the sprinkler is even with the front edge of the light cove (the same as it would be if a soffit was above the cove), the distribution is acceptable. This leaves the question of whether it has an acceptable activation time. It should noted that there is also an allowance whereby the sprinkler can be installed in the same wall above the cabinet provided that there is a clearance of at least 3 ft between the sprinkler and the top of the cabinet. The 3 ft is needed to ensure the distribution is not excessively obstructed. I mention it because it shows the sprinkler activation time is acceptable without a soffit above the cabinet. Actually, the activation time will likely be faster with your arrangement. This is because the sprinkler will be directly in the plume if the heat is flowing up from beneath the light cove and if flowing across the ceiling, the space above the light cove has a much smaller volume than the cabinet with a 3 ft clearance. As with all things not specifically addressed by the standard, obtain approval by the AHJ.
Technical Update is prepared by the Technical Services Dept. of the AFSA: Vice President of Engineering and Technical Services Roland Huggins, a PE registered in fire protection engineering; Phill Brown, a NICET IV certified automatic sprinkler technician and NFPA Certified Fire Protection Specialist (CFPS) and Tom Wellen, a PE registered in fire protection engineering. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright 2016, American Fire Sprinkler Association. All Rights Reserved Training Calendar AFSA Beginning Fire Sprinkler System Planning School 2016 Schedule April 4 - 15, 2016 May 16 - 27, 2016 July 18 - 29, 2016 Oct. 3 - 14, 2016 For more info, call: 214-349-5965 ext. 132
