20 Dec Navigating recent changes
NFPA 72 provides the latest safety provisions to meet society’s changing fire detection, signalling, and emergency communications demands. In addition to the core focus on fire alarm systems, the Code includes requirements for mass notification systems used for weather emergencies; terrorist events; biological, chemical, and nuclear emergencies; and other threats. NFPA 72-2019 contains important updates about Class N pathways, elevator recall and more. Rodger Reiswig, Fellow and VP of Industry Relations, Johnson Controls shares vital information regarding this latest version.
In 2019, nfpa 72 was significantly updated to help support modern buildings and the growing use of the Internet of Things (IoT) and connected technologies. This most recent edition includes more than 200 changes that impact the application, installation, performance, inspection, testing and maintenance of fire alarm systems as well as fire and emergency warning equipment. The changes range from minor edits of terminology to major new processes that directly impact architects, engineers, contractors, building owners and facility managers. Even if your jurisdiction has not immediately adopted the 2019 edition of NFPA 72, it’s important to know what the code now covers.
Elevator recall and evacuations
Updates to the Occupant Evacuation Elevators (OEE) standard now provide full codification of requirements and procedures like how to shut down elevators, signage and smoke detector requirements and more. This is an important change for the Middle East due to recent rapid growth of tall buildings and should become a go-to resource when specifying elevator operations.
The ability to use elevators to evacuate occupants now requires tighter integration between the elevator controller and the fire alarm system. The systems need to convey greater detail from the fire alarm to the elevator controller including which smoke alarms have been activated and where in the building the fire is spreading. All of this affects how the controlled evacuation process is executed.
Also new to NFPA 72-2019 – the elevator controller must now provide greater details to the fire alarm system including the location of the elevator car and time it will take to get to the landing. This information is used to provide voice instructions to various floors as well as instruction for visual displays indicating the elevator’s time of arrival.
Systems must also have the ability to convey dynamic emergency messages to occupants. These messages should inform whether an elevator is available and safe to use for evacuation, if the elevator is stalled or delayed as well as other instruction for safe elevator evacuation. In addition, elevators that are intended to support occupant evacuation during a fire event must now have water runoff areas to prevent discharged sprinkler system water from entering the elevator shaft.
The close integration of fire alarm and elevator systems means building owners will now be required to combine fire alarm inspection with elevator inspection in order to test both technologies as an integrated system. This includes testing the fire alarm activation system, as well as the system that provides information to the emergency display signs and audio
Revisions to class n pathways
The 2016 edition of NFPA 72 created a new circuit designation called Class N pathways. These pathways permit the use of non-life safety networks and ethernet when interconnecting life safety systems. Class N pathways opened up a world of opportunity and flexibility for professionals who design and build fire alarm systems. NFPA 72-2019 now provides more guidance on how life safety and other building systems can share these pathways.
This represents an important advance in smart building technology and the integration of building and life safety systems. As IoT expands into life safety, it’s important to become familiar with these new developments and take advantage of the new and innovative technologies.
Along with the technology requirements for how Class N pathways should function, there is also new guidance for implementation. This includes details around how routers or hubs are distributed, what ports will be used, the location of all ports and where they are connected. It’s also important to note that when IT-based equipment is upgraded, a new maintenance plan needs to be developed in tandem.
Within NFPA 72-2019, there are options as to how life safety systems can be integrated with the building network. This is referred to as shared pathway designations. Based upon the life safety objectives, designers have the option to choose whether the life safety system should be segregated from non-life safety systems and if life safety systems should have priority over data from non-life safety systems.
This update allows other systems to share information and act upon it, when necessary. A fire alarm system will still need to be on its own network. However, updates to Class N pathways allow for the fire alarm system to transmit all required data for HVAC, lighting control and elevator control on a single network rather than traditional hardwired relays.
Simplifying carbon monoxide detection
In the past, carbon monoxide detection was covered by a separate standard, NFPA 720, Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment. This became an issue, since NFPA 720 and NFPA 72 were not aligned, which caused unnecessary complication during design and specification. With the 2019 edition, all carbon monoxide information from NFPA 720 has been incorporated into NFPA 72.
The latest edition now provides explicit direction on the number and location of carbon monoxide detectors to satisfy building code requirements and design for an optimal life safety system. Building owners and managers should review these specifications soon and begin working them into design plans. Housing all requirements for carbon monoxide detection within one standard allows designers, installers and inspectors to reference a single document instead of two.
Although there were no significant changes made during the incorporation of NFPA 720 into NFPA 72, there have been a few minor modifications, including:
- Chapter 14, which covers inspection, testing and maintenance, is updated to include visual and functional testing methodology for carbon monoxide detectors.
- Chapter 23 covering protected premises alarm and signalling systems now offers clarification on several items, including:
- how carbon monoxide detectors are connected to a fire alarm control unit
- how signalling of audible appliances with temporal patterns should be accomplished
- how these detectors should be transmitted to a supervising station.
- Chapter 29, which houses requirements mainly for residential applications, includes the incorporation of carbon monoxide for residential protection. This will help the integration of smoke alarms and carbon monoxide alarms and how they notify occupants. Signalling, powering, and tandem device connection are all now included in Chapter 29.
Visual alarm notifications
Research has shown that people’s reaction to visual alarm devices (VAD) is influenced by several factors, including the duration of the light pulse and the illumination level. Often, a shorter pulse duration (20 milliseconds [ms]) at the proper required candela will yield a faster reaction. Recent UL research shows that increased candela output (illumination level) in devices with a longer pulse duration can generate the same level of responsiveness as 20ms appliances. Because of this, NFPA 72-2019 now allows for the use of VADs with a light pulse duration of longer than 20ms and shorter than 100ms for direct viewing applications such as corridors. To comply, it must be demonstrated that the longer-pulse device is equal or superior to standard devices that use 20ms pulse notifications. The NFPA 72-2019 annex provides guidance on how to achieve this.
NFPA 72-2019 also recognises that ambient lighting plays an important role in VAD performance. New requirements were added that provide guidance for the selection of VADs for environments with ambient lighting conditions.
Control unit mounting requirements
Until now, there has never been direction on how high or low a fire alarm control unit could be placed on a wall. As a result, some fire alarm units were mounted so high they required the use of a step ladder for some people to deploy. There have also been instances where equipment was placed above the ceiling. This prompted the need to define maximum and minimum mounting heights for an average user to be able to easily interact with the system.
Because of this change, it’s critical that wall space for fire alarm control units is identified in the early stages of specification. Designers should indicate exactly where smoke detectors or audio/visual units are to be placed in addition to how the fire alarm control unit should be defined. Every bit of space should be accounted for and documented to avoid confusion and ensure the proper amount of space is allocated for the fire alarm control unit.
Getting started now
There are other changes addressed in NFPA 72-2019 that cover supervising stations, inspection, testing, maintenance and more – it can be downloaded from nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=72 as it is a good idea to familiarise yourself with these updates so you’re prepared once your jurisdiction adopts this version. For additional resources to help you comply with standards and protect your buildings, visit autocall.com/resources.