What does it take to reliably wake someone from a sound sleep when there is the threat of a fire or detection of carbon monoxide in the building?
The National Fire Protection Association (NFPA) has generated new requirements in the NFPA 720 Standard for Installation Carbon Monoxide (CO) Detection and Warning Equipment, all aimed at maximizing those precious seconds between the initial sound of an alarm and when individuals are able to get to safety.
Studies conducted by the Fire Protection and Research Foundation (FPRF) on high risk groups, including children, hearing-impaired individuals, and those under the influence, have driven the changes in the new codes. The research revealed that a square wave sound with a lower-range frequency is the most effective signal to awaken people versus the current high-pitched fire alarm signal.
In 2009, the NFPA 720 code expanded to mandate Carbon Monoxide (CO) detection with a low frequency alarm (listed as a T4 signal) in areas with sleeping occupants. Shortly thereafter, the 2010 edition of the NFPA 72 National Fire Alarm and Signaling Code required sleeping rooms to be fitted with T3 pattern low frequency alarms for fire detection. These updated codes took effect on January 1, 2015.
For building owners and facility managers, understanding the new code and how it applies to a particular structure is critical.
What does the code state?
The new NFPA 720 code mandates that audible alarms in sleeping rooms need to be able to produce a low frequency T4 pattern along with a T3 pattern to effectively wake individuals if CO or fire is detected. NFPA 720 and NFPA 72, which went into effect last January, include similar low frequency requirements for sleeping areas. However, the T4 (NFPA 720) and T3 (NFPA 72) signals are two completely different sound patterns based upon the detected condition so those occupying the building can distinguish the type of emergency.
What types of facilities are required to comply with the updated code requirements?
The updated code is aimed primarily at commercial locations where people sleep, including:
- Hotel/motel guest rooms
- College/university dorm rooms
- Assisted living facilities
- Apartment buildings
- Any areas that might be used for sleeping, i.e. living room of an apartment or condominium as it may have sleeping occupants
What frequency of tone must be used to be compliant?
Section 22.214.171.124, in both the 2009 and 2012 NFPA 720 editions, mandates that the alarm signal must be a square wave with a frequency of 520 Hz + 10%.
How effective are these alarms?
Three NFPA-petitioned research projects in 2006 led to the new requirements for tones used to wake people. The findings from these studies showed that a low frequency 520 Hz square wave signal was more effective at waking people who were impaired by alcohol or had hearing loss. In fact, the low frequency 520 woke 92 percent of the participants in the study that had hearing difficulties.
The new requirements mean building owners and facility managers need to be even more vigilant about the current alarm systems in their buildings. Reviewing those systems, conducting an audit of the options in the marketplace to update those systems and then making the necessary updates will ensure compliance with the law. It will also go a long way toward keeping occupants safer, especially when an emergency situation arises.
Ted Milburn is vice president of marketing for Eaton's notification business, reach him at firstname.lastname@example.org.
Currently rated by 0 people