Look, Listen And Comprehend

Although the 2013 edition of the National Fire Alarm and Signaling Code contains 15 chapters and nine annexes, I find many contractors, designers and authorities having jurisdiction reference only one or two chapters when deciding what requirements will affect their fire alarm system design, installation or approval. I call this “using the code in a vacuum.”

A user can view the code as having four major subdivisions: administrative chapters, support chapters, system chapters and usability annexes. Each subdivision contains the representative chapters: the administrative division contains chapters 1–9; the support division contains chapters 10–19; the systems division contains chapters 20–29; and the usability division contains annexes A–I.

The interrelationship between all of the chapters and, in some cases, the annexes helps ensure compliance with all requirements and guidelines in the code.

Users simply cannot read the code like a Tom Clancy novel. For one thing, it does not provide as much excitement. Nevertheless, a user must still read the code and use it in its entirety. Failing to do so will likely mean a fire alarm system under the user’s care will not meet the stated requirements.

The only exception is Chapter 29, Single- and Multiple-Station Alarms and Household Fire Alarm Systems. It stands alone, unless there is a specific reference to another chapter’s requirements.

Chapter 1 advises: “NFPA 72 covers the application, installation, location, performance, inspection, testing, and maintenance of fire alarm systems, supervising station alarm systems, public emergency alarm reporting systems, fire warning equipment and emergency communications systems (ECS), and their components.” In addition, it states, “The provisions of this chapter apply throughout the Code unless otherwise noted.” Therefore, a user is instructed to include the requirements of Chapter 1 unless modified by one of the other chapters.

The application section paragraphs—such as the one found in Chapter 21, Emergency Control Function Interfaces—state, “The requirements of Chapters 7, 10, 17, 18, 23, 24 and 26 shall also apply, unless they are in conflict with this chapter.”

As an example of chapter interrelationship, review the requirements for intelligibility found in Chapter 24. Section 24.3.1 requires that, “Emergency communications systems shall be capable of the reproduction of prerecorded, synthesized, or live (e.g., microphone, telephone handset, and radio) messages with voice intelligibility in accordance with Chapter 18.”

In the intelligibility section of Chapter 18 (18.4.10) are five paragraphs containing requirements. The first paragraph introduces the requirement for voice intelligibility in every acoustically distinguishable space (ADS) and states that all prerecorded, synthesized or live messages must be intelligible. Because the definitions section of the code has defined the words “acoustically distinguishable space,” we must review Chapter 3 for its definition. Chapter 3 defines acoustically distinguishable space as, “An emergency communications system notification zone, or subdivision thereof, that might be an enclosed or otherwise physically defined space, or that might be distinguished from other spaces because of different acoustical, environmental, or use characteristics, such as reverberation time and ambient sound pressure level.” In addition to this definition, Annex A provides a significant amount of additional explanatory material for this term.

Paragraph requires a fire alarm system designer to determine the acoustically distinguishable spaces during the planning and design of the emergency communications system. In response to this requirement, an authority having jurisdiction may require that the designer submit the ADS assignments for review and approval.

In addition, the designer must identify whether each of the ADSs requires intelligibility. Annex A offers guidance for certain ADSs where a designer may not need to meet the intelligibility requirement. These include eight locations: private bathrooms, shower rooms, saunas, and similar rooms/areas; mechanical, electrical, elevator equipment rooms, and similar rooms/areas; elevator cars; individual offices; kitchens; storage rooms; closets; and rooms/areas where intelligibility cannot reasonably be predicted.

Annex A suggests that, to meet the code’s requirements, a designer must include ADS assignments as a part of the design process and, where a building has more than one ADS, include the boundaries of each ADS on the design drawings.

And finally, Paragraph indicates that, in acceptance testing, a contractor does not need to use quantitative measurements. That said, the code allows a contractor to take these measurements, and in some acoustically challenging spaces, a contractor will find it necessary to measure intelligibility to validate the model used for speaker placement.

In the matter of chapter interrelationships, note that all of this information became disclosed by taking note of that simple statement in Chapter 24 that advises the provision of voice intelligibility “in accordance with Chapter 18.” This represents only one example of the interrelationship between chapters in NFPA 72 2013. My advice: Never use the code in a vacuum!

About the Author

Wayne D. Moore

Fire/Life Safety Columnist
Wayne D. Moore, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a principal member and past chair of NFPA 72, Chapter 24. Moore is a vice president with JENSEN HUGHES at the Warwick, R.I., office. He c...

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