Mass notification systems (MNS) communicate emergency situations involving non-fire emergencies to building occupants (and individuals in an area surrounding a building) using audible and visual means. Mass notification systems are governed by NFPA 72, Chapter 24 (Emergency Communications Systems). Chapter 24 covers requirements for mass notification systems, fire alarm voice evacuation systems, fireman’s telephone and radio systems, area of refuge communications, and elevator communications.
While mass notification systems and fire alarm voice evacuation systems both use voice messaging (speakers) and visible (strobes) to alert building occupants, the difference between the systems is the action that the systems instruct the occupants to take. Fire alarm voice evacuation systems typically instruct the occupants to evacuate the building (“there’s a fire, get out”).
Mass notification systems notify occupants of other emergencies that may not necessarily require building evacuation. Mass notification systems may give specific instructions based on the type of emergency. For example, for a tornado warning, the instructions may be to shelter in place, or for a chemical spill it may be to report to a specific safe area within the building. For both of these emergencies, having the occupants evacuate the building would not be the best action to take.
Mass notification systems are classified as in-building and wide area systems. In-building systems provide occupant notification within a building (just like fire alarm voice evacuation). Buildings that require voice evacuation per the building code and have a need for mass notification as well will often install a combination MNS/voice evacuation system like the 5820XL-EVS, allowing both functions to be performed by a single system.
Wide area systems provide outdoor notification using high power speaker arrays. Wide area systems may also use distributed recipient mass notification systems (DRMNS) such as text messaging, email, or reverse 911.
Similar Fire and MNS Requirements
The notification requirements for mass notification systems have the same requirements as fire alarm (per NFPA 72, Chapter 18). Speaker/strobes are most commonly used for in-building notification, with the same mounting and spacing requirements as fire alarm. NFPA 72 permits using the same notification appliances for fire alarm and mass notification purposes, but the appliance must have no marking or be marked “ALERT”. A “FIRE” marking is not permitted for notification appliances used for both purposes to help avoid confusion.
About the Author
Bryan McLane is a 33 year veteran of the security and fire industry. He is currently Vice President of National Training Center, the provider of “The Very Best in Training” to the security and fire industry.