Security Watch: Inside ISO’s New Fire Detection and Alarm Standard

Q&A with Peter Parsons on the international design and installation guidelines


       

How was the standard developed?

ISO 7240-14 was developed by a Working Group of technical experts established by ISO committee ISO/TC 21/SC 3, Fire detection and fire alarm systems. The committee has participating membership of 31 countries, with an additional 14 countries as observing members. Over the past decade, ISO/TC 21/SC 3 has published 31 Standards and other documents related to fire detection and fire alarm systems for buildings. Twenty two of these Standards are for products, including components such as detectors, audio and visual alarm devices, and control and indicating equipment.

 

What are the differences between this standard and NFPA 72 (and any other applicable NFPA standards)?

ISO 7240-14 and NFPA 72 share the same goal of providing early fire detection and safe egress for building occupants. Although ISO 7240-14 includes requirements for fire detection and alarm systems that may be connected to a monitoring service provider, equipment at the monitoring station is outside the scope of this Standard. Likewise, fire detection within residential dwellings is also outside the scope of ISO 7240-14. ISO 7240-14 has been developed for application in non-dwelling buildings.

Products used in the design of the fire detection and alarm system are required to comply with the requirements of other parts of ISO 7240 (eg detectors, audio/visual alarm devices, modules, alarm transmission equipment, etc). Use of this equipment has simplified the requirements in ISO 7240 because the equipment Standards are not technology dependent. For example, ISO 7240-14 does not need to include specific requirements for alarm transmission equipment, such as specifying the types and numbers of transmission paths from the building to the monitoring service provider.

The largest part of ISO 7240-14 relates to the design of the fire detection and alarm system (contained in Clause 6). Design is required to be undertaken using a systematic and documented process. All assumptions, reasons for equipment selection and site-specific information (such as building construction, use, egress paths, etc) shall be considered as part of the design process. A well-documented design is critical to ensure the performance requirements of the fire detection and alarm system can be achieved, and assists with both installation, commissioning and any modifications that may be made in a future time.

The designer needs also to be aware of the regulatory regime that may exist. National or regional regulations that place other limitations on the design need to be factored into the final configuration of the fire detection and alarm system. These may include limitations on the number of devices that can be configured within a detection or alarm zone, the use of installation materials (such as fire-rated cabling), and any requirements for the remote monitoring of fire alarm and fault conditions. Where external constraints permit, Clause 6 provides complete requirements on detector selection and location, requirements for manual call points, and requirements for fire alarm devices.

Fire alarm signalling to building occupants is important for the safe egress of people from the building. ISO 7240-14 allows the use of both audio/visual alarm devices installed throughout the occupied areas, and the use of a sound system for emergency purposes. The sound system is specified in ISO 7240-16, and the design and installation requirements are specified in ISO 7240-19. ISO 7240-19 is a complementary Standard to ISO 7240-14, with both parts having a similar style. For larger buildings where a simply notification solution is not appropriate, ISO 7240-19 provides a solution.

Fire detection and alarm systems are often connected to other building systems. Requirements for smoke and heat control (such as fire doors), remote monitoring and interfacing to other building systems (eg HVAC, building management systems) are also included in Clause 6.