In my July 2023 web exclusive, I tackled questions often raised by those in the field trying to understand the requirements that affect their fire alarm system installations. Below is the same format.
Does wireless technology represent the future of the industry?
As you no doubt realize, NFPA 72-2022, National Fire Alarm and Signaling Code, has an entire section devoted to low-power wireless fire alarm technology in 23.16. These requirements focus on fire alarm initiating devices that communicate with a fire alarm system control unit using a low-power wireless transmission method.
Additionally, as stated in Annex A of the code, “For the 2022 edition of the Code, new requirements have been added that affect the operation of the pathways that are used to transmit signals between the devices and the control unit of a wireless fire alarm system. The requirements are similar to the pathway requirements for wired pathways of the same class of circuit. Just like a Class B wired pathway, Class B radio pathways do not include a redundant pathway. The capability of the pathways must be verified to be end-to-end operational, and a trouble signal is to be produced if the intended operation of the pathway is compromised in some way. As in the case with a Class B wired circuit, operation of the Class B wireless path stops at the spot where the pathway is somehow affected, such as in the loss of a repeater. Finally, in order to maintain a sufficient power supply to operate, each transceiver or repeater must be provided with primary and secondary power like a traditional fire alarm system (see Section 10.6) or be provided with multiple primary batteries as required by 23.16.2.2.”
There are also new wireless “mesh networks” recognized by NFPA 72. A helpful diagram is shown in the handbook on page 717. NFPA 72-2022 also has Section 26.6, which is devoted to wireless means of transmitting fire alarm, supervisory and trouble signals from a protected premises to a supervising station. This section has requirements for two-way radio frequency (RF) multiplex systems as well as one-way private radio alarm systems. For each type of system, only a limited number of manufacturers have obtained listing. While the idea of wireless systems has great appeal, a potential user needs to create a very careful cost analysis between wireless and nonwireless technologies. Each individual application will have unique features that may skew the analysis in one direction or the other.
In some cases, wireless technology has distinct installation advantages, while nonwireless technology will have an edge in others. The key to choosing any technology rests with using listed components and systems. By meeting the requirements of NFPA 72-2022 chapters 10, 12 and 23, a facility owner can help assure a baseline level of quality for an installed fire alarm system.
Chapter 10 requires “Equipment constructed and installed in conformity with this Code shall be listed for the purpose for which it is used.” What does the future of fire alarm systems hold? No one really knows for certain. Likely, wireless technology will play an increasing role over time, but the tradeoff from saving money up front in installation costs may be lost on the backend of continued battery replacement and maintenance.
The owner of a facility has requested just one smoke detector in the entire facility: installed over the coffee pot in the office kitchenette. Will the authority having jurisdiction have the right to require other detectors to cover that room? What about the rest of the building?
The answer to your first question is no. NFPA 72-2022 permits partial or selective coverage. It also permits nonrequired coverage. Please note the following sections:
“17.5.3.2 Partial or Selective Coverage. Where codes, standards, or laws require the protection of selected areas only, the specified areas shall be protected in accordance with this Code.
“A.I7.5.3.2 If there are no detectors in the room or area of fire origin, the fire could exceed the design objectives before being detected by remotely located detectors. When coverage other than total coverage is required, partial coverage can be provided in common areas and work spaces such as corridors, lobbies, storage rooms, equipment rooms, and other tenantless spaces.
“The intent of selective coverage is to address a specific hazard only. Where a specific area is to be protected, all points within that area should be within 0.7 x the adjusted detector spacing for spot-type detectors as required by 17.6.3 and 17.7.3.2. Note that an area does not necessarily mean an entire room. It is possible to provide properly spaced detectors to provide detection for only part of a room.
“Similarly, the Code permits protection of a specific hazard. In that case, detectors within a radius of 0.7 x the adjusted detector spacing from the hazard provide the required detection. An example of protection of specific risk is the smoke detector required by Section 21.3 to be within 21 ft (6.4 m) of an elevator, where elevator recall is required.
“It should also be noted that fire detection by itself not fire protection. Also, protection goals could be such that detection being provided for a specific area or hazard might require a form of total coverage for that particular area or hazard. That is, it might be necessary to provide detectors above suspended ceilings or in small closets and other ancillary spaces that are a part of, or an exposure to, the area or hazard being protected.
“17.5.3.3 Nonrequired Coverage.
“A.I7.5.3.3 The requirement of 17.5.3.3 recognizes there will be instances where, for example, a facility owner would want to apply detection to meet certain performance goals and to address a particular hazard or need, but that detection is not required. Once installed, of course, acceptance testing, annual testing, and ongoing maintenance in accordance with this Code is expected. The intent of this section is to allow the use of a single detector, or multiple detectors provided for specific protection, with spacing to meet specific fire safety objectives as determined in accordance with 17.6.1.1 and 17.7.1.1.
“17.5.3.3.1 Detection installed for reasons of achieving specific fire safety objectives, but not required by any laws, codes, or standards, shall meet all of the requirements of this Code, with the exception of the prescriptive spacing criteria of Chapter 17.
“17.5.3.3.2 Where nonrequired detectors are installed for achieving specific fire safety objectives, additional detectors not necessary to achieve the objectives shall not be required.”
As you can see from these requirements, particularly 17.5.3.3.2, the code does not extend the right to an AHJ to insist on additional detection. However, if the building code enforced by the jurisdiction, a previously written statute of the jurisdiction or the requirements of a private AHJ, such as an insurance company, requires the facility to have additional fire detection devices, then the owner would need to comply.
Where can I find some examples that will help me learn the proper way to fill out the “Emergency Communications Systems Supplementary Record of Inspection and Testing” form that appears in the code in Chapter 7?
The National Fire Protection Association publishes a companion volume to NFPA 72-2022 known as the National Fire Alarm and Signaling Code Handbook. Starting on page 158 is an example of a filled-out version of the System Record of Inspection and Testing form. Following that are all the additional forms required by Chapter 7, including Figure 7.8.2(k), Emergency Communications Systems Supplementary Record of Inspection and Testing. This example should materially assist you in learning how to properly complete this important document. You will find similar aids throughout the handbook.
About The Author
MOORE, a licensed fire protection engineer, was a principal member and chair of NFPA 72, Chapter 24, NFPA 909 and NFPA 914. He is president of the Fire Protection Alliance in Jamestown, R.I. Reach him at [email protected].