A fire alarm system is used to alert building occupants to the presence of smoke or fire. This early warning signal is designed to evacuate the building more quickly, which can minimize injury and death during an emergency. Fire alarm system design is tightly regulated throughout the U.S. in order to ensure proper materials and techniques are used.
The use of fire alarm systems in regulated by local building codes, which tend to differ between regions. During the permitting process, the project design team will coordinate with local authorities to determine whether a fire alarm system is needed. When this system is required, it is generally designed in accordance with standards developed by the National Fire Protection Association (NFPA). NFPA Standard 72 defines proper fire alarm system design. Though this standard is not a law, it has been adopted by most governing bodies in the U.S. with minimal modification.
Each state has slightly different requirements about who can design a fire alarm system. Generally, an architect or engineer may design this system and submit it for approval by the state. In many areas, a specialty contractor or consultant may design the system. Any nonlicensed fire alarm designer must usually be certified by the National Institute for Certification in Engineering Technologies (NICET), though this varies from region to region. Once the system is designed, it must be submitted for approval by the local fire marshal or permitting agency. In most cases, fire alarm drawings are created apart from the rest of the building plans and reviewed by different agencies. This is due to the special risks and considerations associated with fire protection.
Fire Alarm Components
Most fire alarm systems are controlled by a central control panel. The panel is powered by a dedicated electric supply, then backed up by a generator or battery backup in case of an electrical failure. Depending on the size of the building, the system may be designed as manual or automatic. A manual system is operated by a pull station or other manual action, while automatic systems are activated by sensors or detectors. Upon activation, the panel sends a message to signal devices to warn occupants of a fire. These signal devices may include strobe lights, horns, alarms or spoken-word instructions. As the building is being evacuated, the system may also alert other building components to the emergency. For example, signals can be sent to release doors being held open by magnets or to close duct dampers to prevent smoke transfer.