NFPA Journal - May/June 2012 - (Page 71)

— . CODES IN REVIEW . — NFPA 13 cated to performance-based protection approaches for storage applications. Although the authority having jurisdiction has always had the opportunity to approve a performance-based design approach through the equivalency clause in Section 1.5, it has never been clearly defined as to what must be submitted to support the approach. The new Chapter 21, “Alternative Sprinkler System Designs for Chapters 12 Through 20,” provides manufacturers and designers with the information necessary to implement an alternative design approach. Sloped Ceilings NFPA’s residential sprinkler design standards have never clearly defined how to determine the appropriate number of sprinklers that need to be calculated under a sloped ceiling or a ceiling with beams. This has led to a range of opinions on how to handle these situations and has added to the challenges of implementing sprinkler system designs in occupancies with such ceilings. In 2010, the Fire Protection Research Foundation sponsored a project conducted by Hughes Associates to determine if there was a way to better quantify the impact of these ceiling arrangements on system design. The information gathered in the study, Analysis of the Performance of Residential Sprinkler Systems with Sloped or Sloped and Beamed Ceilings, available at nfpa.org/ foundation, was used to develop code language that provides five common ceiling arrangements that can use the “two-sprinkler hydraulic calculation” found in NFPA 13D and the “foursprinkler hydraulic calculation” found in NFPA 13R without the need for each arrangement to be included in the listing for the sprinkler. 10 Water Mist Systems One of the common themes during the code-development process for the 2013 editions of NFPA 13, NFPA 13R, and NFPA 13D was whether water mist systems fit into the definition of an automatic sprinkler system. The sprinkler technical committees acknowledged the benefits of water mist systems, but determined that, due to differences in design intent and functionality, they cannot be considered automatic sprinklers. Each of the standards added language to send users to NFPA 750, Water Mist Fire Protection Systems, which provides direction on these systems, as they do not fall under the scope of the NFPA 13 technical committees. 11 12 as to where sprinklers need to be provided where cloud ceilings exist. The Fire Protection Research Foundation is currently reviewing a proposal to conduct testing on cloud ceiling arrangements that would provide the committee with more data to consider when developing the next edition of the standard. Cloud Ceilings Another topic that has seen much debate over the years is sprinkler system design for cloud ceilings, which are “floating” ceiling panels installed below the main ceiling that do not make a complete wall-to-wall horizontal surface. Cloud ceilings are becoming more and more prevalent in architectural design, and many NFPA 13 users are looking for a specific section that addresses this concept. While the Technical Committee for Sprinkler System Installation Criteria reviewed potential language addressing sprinkler protection for cloud ceilings, the concepts were not supported by full-scale testing and were not adopted into the standard. The use of the obstruction rules in Chapter 8 will continue to provide direction ESFR and CMSA Sprinklers Another loop closed in the 2013 edition of NFPA 13 surrounds the use of control mode specific application (CMSA) and early suppression fast response (ESFR) sprinklers in light- and ordinary-hazard occupancies. The standard has never formally stated that these types of sprinklers are permitted in light- and ordinaryhazard occupancies, as they are typically associated with storage protection. This lack of clarity has led to debates in the field as to whether the omission of a declarative allowance of these devices in light- and ordinaryhazard occupancies was by design. This has been an increasingly common problem as buildings are being turned over, and fire and building officials require the new owners to replace existing ESFR and CMSA sprinklers with sprinklers more commonly associated with light-hazard occupancies (i.e., K-5.6) where the occupancy hazard is being reclassified to lightand ordinary-hazards. The ESFR and CMSA sprinklers will easily meet the density requirements required for light- and ordinary-hazard occupancies and will now be explicitly permitted to protect these areas. Matt Klaus is a senior fire protection engineer and staff liaison for NFPA 13, NFPA 13R, and NFPA 13D. 13 MAY/JUNE 2012 NFPA JOURNAL 71 http://www.nfpa.org/foundation http://www.nfpa.org/foundation

Table of Contents for the Digital Edition of NFPA Journal - May/June 2012

Nfpa Journal - May/june 2012
Contents
First Word
In a Flash
Perspectives
Firewatch
Research
Heads Up
Structural Ops
In Compliance
Buzz Words
Outreach
Electrical Safety
Wildfire Watch
Treasurer's Report
Signal Concern
Giant Steps
13^3
Sprinklered Menagerie?
Free Samples
Eye on Health Care
Membership: The Sections
Expo Preview: Exhibitors' Showcase
Looking Back

NFPA Journal - May/June 2012