It is helpful to know when a system is required and when it is not. It’s important to know when you must monitor other building equipment such as duct detectors and kitchen hood systems. The codes use certain language to differentiate required and nonrequired fire alarm systems. 

Here is a good example. Let’s say you have a strip mall that requires a “supervised” sprinkler system. This means you will have to install a fire alarm system to monitor the sprinkler system. This is typically called a dedicated function fire alarm system because that is all it has to do. You are not required to connect duct detectors or any notification appliances. Remember, the code only required a supervised sprinkler system, not a building fire alarm system. You do still have to install a smoke detector over the panel and have one pull station. There have been many interpretations in the past that if you install this fire alarm system, you have to have occupant notification, but that was not the code requirement.

Wording is important

Required fire alarm systems are mandated by building, fire and life safety codes. How the code is worded is important. Section 907 of the International Building Code (IBC) reads, “An approved fire alarm system installed in accordance with the provisions of this code and NFPA 72 shall be provided in new buildings and structures in accordance with Sections 907.2.1 through 907.2.23 and provide occupant notification in accordance with Section 907.5, unless other requirements are provided by another section of this code.” 

It then goes through each occupancy classification to say what is required. It tells users when and where smoke detection and pull stations must be provided, and that you must have occupant notification unless there is a modification elsewhere in the code. You will find similar requirements for sprinklers in Section 903.

The code may also say that you must connect other equipment when there is a building fire alarm system. Other times it may say you must connect this equipment where there is a “required” fire alarm system. The codes may also have thresholds that must be exceeded before a fire alarm system is required.

Code requirements

Here is an example of the language used in NFPA 90A, Standards for the Installation of Air-Conditioning and Ventilating Systems: “6.4.4.2 In addition to the requirements of 6.4.3, where an approved fire alarm system is installed in a building, the smoke detectors required by the provisions of Section 6.4 shall be connected to the fire alarm system in accordance with the requirements of NFPA 72, National Fire Alarm and Signaling Code.” 

Approved means acceptable to the authority having jurisdiction (AHJ) and usually means it is a system required by code. As always, when in doubt, it is best to discuss that with your AHJ.

It may also state what is required, such as, “6.4.4.2.1 Smoke detectors used solely for closing dampers for heating, ventilating, and air-conditioning system shutdown shall not be required to activate the building evacuation alarm.” IBC Section 907.3.1 states, “Duct smoke detectors shall be connected to the building’s fire alarm control unit where a fire alarm system is required by Section 907.2.” The codes will also tell you if you have to monitor the fire alarm system or not.

Unfortunately, not all requirements are in the same location. Knowledge of where to look for various requirements is key to installing a correct functional system.

Nonrequired fire alarms

Nonrequired fire alarms are systems not required by code language, but installed at the request of the owner or fire alarm designer. They are typically installed to provide fire protection in a certain section of a building when systems are not required. NFPA 72 states that “23.3.2.1 Nonrequired protected premises systems and components shall meet the requirements of this Code.” This means that if you install any devices, they must be installed the same as if they were required.

One exception is that smoke detectors do not need to meet the spacing requirements in Chapter 17 of NFPA 72. However, from a liability point of view, be very careful if you install less than what is required. It also means that installed equipment must be tested correctly in accordance with Chapter 14. There are no requirements for providing monitoring for nonrequired systems.

Learning how to properly use the codes will make your job a lot easier and will ensure code-compliant systems. Every situation is different, so remember the codes are minimum requirements, and it may be better fire protection to provide more than the minimum.

stock.adobe.com / Satawat Anukul