According to the U.S. Fire Administration (USFA), there were 414,000 residential fires in 2007, taking the lives of 2,895 men, women, and children and injuring another 14,000. According to the National Fire Protection Agency (NFPA), “Homes with a smoke detector typically have a death rate that is 40 to 50 percent less than the rate for homes without a smoke detector.” I should add at this point that this statistic only applies to homes where the smoke detectors were properly installed and were operational. This guide will help you select the proper detectors for your home and explain what you need to do to install and maintain them properly.
Visit any home center and you will find smoke detectors that are battery operated and smoke detectors that are hardwired. A hard-wired smoke detector is one that requires direct connection to the 110-volt wiring in your home. Hardwired detectors are also required by code to have a battery backup that will keep the detector operational during power outages. Many people buy the straight battery powered detectors because they are the easiest to install but recommended way to go is with hardwired detectors that have a built in battery backup. In fact, most local building code enforcement departments require that hardwired detectors be used in all new construction.
There are two types of smoke detector, ionization detectors and photoelectric detectors. Both are effective smoke detectors and meet the same rigorous UL (Underwriters Laboratory) standards however, the ionization type responds faster to flaming fires which produce smaller combustion particles then the photoelectric detectors. The photoelectric detectors, on the other hand, respond quicker to smoldering fires then the ionization type of detectors. Combination units that incorporate both the ionization and photoelectric types in one unit are the best choice. Kidde, one of the world’s most respected manufacturers of smoke alarm equipment sell combination hardwired units for about $45 each and straight battery powered combination units for about $30 each.
The NFPA Publication 72, The National Fire Alarm Code, requires that detectors be placed in each bedroom, outside each bedroom in hallways, on each floor of a multistory dwelling at the base and top of stairwells. Detectors should also be installed in the kitchen, laundry room, furnace room, attic, basement, garage, and any other area where a fire is likely to start. Most municipalities require that all smoke detectors on a given floor be interconnected, so check with your building codes department to see if this regulation applies to you before you start your project. If it does, you will have to “fish” the required four-conductor cable through the floors, walls, and ceiling to interconnect them. In any case, NFPA 70 requires that all AC/DC units be connected to a dedicated, non-switched branch circuit, so you will have to run Romex cable all the way back to the service panel for that circuit. This dedicated 110-volt branch circuit needs to be protected by an AFCI (Arc Fault Circuit Interruption) Device at the service panel. Check with your local code enforcement officer before installing this circuit because you may need to pull a permit before installing the system.
Once you have your new system in place and operating, you need to maintain it religiously. Every week vacuum out the sensors to keep free of dust, pet dander and other contaminants. Once a month check the detectors by pressing their individual test buttons. Change their backup battery every year and any time they emit their low-battery beep, using long lasting batteries.
Although most municipalities will allow the homeowner to do any work that a licensed electrician can do, if you are at all uncomfortable about working in your service panel, you may want to hire a professional electrician to complete that part of your project.
