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Safety and Low Frequency Alarms

​In 2014, the National Fire Protection Association (NFPA) established a new provision requiring all sleeping areas within buildings that have a protected premises fire alarm system to include a low frequency audible alarm signal. However, commercial building operators have been hesitant to endorse the new technology due to its associated costs; low frequency systems consume more power to produce a tone, which may ultimately affect the monthly energy bill.

However, the benefits of low frequency technology are apparent. The peer-reviewed alarm reviewed studies driving the NFPA's requirements have shown that a 520 Hz low frequency alarm is six times more effective in a fire event than the standard 3 KHz audible alarm signal at waking high-risk groups, such as people over 65 years old, people who are hard of hearing, school-aged children, and people who are alcohol impaired.

The low frequency systems should be installed only in sleeping areas, meaning that placing systems in hallways and lobby areas is unnecessary. The sleeping areas that require a low frequency alarm include buildings with a protected premises fire alarm system, such as hotels, university dormitories, assisted living spaces, and multi-family living units such as condominiums.

Costs can be mitigated depending on application and building size. Standalone sounders installed in individual sleeping areas may be better suited for smaller buildings, for example, while integrated low frequency voice evacuation systems are best for larger buildings.

Building operators should consult with their local fire marshals to determine the status of the regulation's adoption and enforcement in their area to assess their timeframe for installation. The next conversation should be with dealers to discuss available options that best fit the building's needs. The ease or difficulty with which the new requirements are deployed will come down to the system and the manufacturer. Low frequency devices that can be easily retrofitted into existing installations are a quick, cost-effective solution for meeting new code requirements. However, it is also important to understand that power supplies, audio source units, amplifiers, sounders, sounder bases, and speakers all play a part in achieving code-compliant 520 Hz signaling. Special design consideration may be required to accommodate low frequency notification in current life safety systems.

As property owners and managers gain a better understanding of the technology, low frequency fire systems are expected to be adopted in residential single-family housing as well. The U.S. Fire Administration indicates that 51 percent of deaths caused by residential fires take place between 11:00 p.m. and 7:00 a.m. There is growing interest within the industry for similar technology in residential homes to provide the same protections for families, especially if the family has a member that is hearing impaired.

Maximizing those crucial seconds between the initial sounds of a fire alarm and waking individuals can save lives. Low frequency technology ensures that everyone can react appropriately when there is an emergency.

Doug Hoeferle is product marketing leader and Christa Poss is senior manager of channel marketing with Honeywell. They work to provide innovative fire safety solutions through Honeywell's fire products team.