Smoke Detectors, Alarm Systems and Upgrades
by Michael Chotiner of The Home Depot


The National Fire Alarm and Signaling Code (NFPA 2013 72) has set standards to transition away from smoke alarms powered by removable 9-volt batteries and encourage the adoption of new technologies.  The most recent version of the code requires smoke alarms to be hard-wired, interconnected, and backed up with a 10-year sealed battery.

It also reinforces requirements for the placement around the home of smoke alarms, namely:

• in all bedrooms and sleeping quarters or on walls or ceilings just outside of bedrooms and sleeping quarters;
• at least one device on each floor of a home, including the basement; and
• wherever flammable substances are stored, such as the garage.

While there’s general recognition at state and local levels that mandating smoke alarm upgrades to the current standard—which requires installation by a licensed electrician—would be onerous for owners of older homes and, therefore, unenforceable, many states throughout the U.S. are now trying to drive upgrades through the permitting process for major interior renovations and additions. In many jurisdictions, if plans involve opening up walls or building new ones, the remodeler/owner must also plan to install hard-wired, interconnected smoke alarms to get a permit.

Some jurisdictions require dual-sensor smoke alarms with both ionization and photo-electric detectors. And some require carbon monoxide detectors to be installed with compliant smoke alarms in an upgrade.
The permitting process is not the only official lever being used to nudge owners and builders into compliance with the latest smoke alarm standards.
Some jurisdictions also mandate replacements and upgrades when:

• ownership of the property changes;
• there is a change of tenant;
• the existing smoke alarm is more than 10 years old; and
• the existing smoke alarm fails to respond or otherwise malfunctions.

Combination Fire- and Burglar-Alarm Systems
Where smoke alarms are integrated with home security systems that also include intrusion alarms, programming keypads, transformers, automatic telephone dialers, and annunciators to sound the alarm, there are additional considerations. While the code allows combination alarm systems, when a fire detection device is present, it becomes a “household fire alarm system” that is subject to NFPA standards.
That means that:

• the equipment used must be listed for use in a fire alarm system [NFPA 72(07)-11.3.1];
• the system must ensure that fire warnings are audibly distinct from other alarm sounds and take precedence, even if a non-fire warning sounds first [NFPA 72(.07)-11.7.6.2];
• the system must have two independent power sources—AC current and a rechargeable battery [NFPA 72(07)-11.6.2 (1)];
• the battery must have the capacity to power the system for at least 24 hours in the event of a power failure, with the capability to recharge within 48 hours [NFPA 72(07)-11.6.2 (2)];
• where common wiring exists in a combination system, components that don’t have a fire detection/warning function must be connected so that any fault in the equipment or interconnection between this equipment and the fire alarm system wiring does not interfere with the supervision of the fire alarm system, or prevent alarm or trouble signal operation [NFPA 72(07)-11.7.6.5];
• when a home fire alarm system is monitored from a remote station, the station may verify the alarm signal as long as it doesn’t delay notification of the fire department by more than 90 seconds [NFPA 72(07)11-7.8]; and
• monitored fire alarm systems are required to send a test once a month [NFPA 72(07)11-7.8].
  

For a valuable guide to smoke alarm standards and related issues, read InterNACHI’s article on Smoke Alarm Inspection.

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​https://www.nachi.org/home-depot-smoke-detectors.htm