Smoke Alarms: How to Install and Maintain Them
Your chances of dying in a fire are cut in half if you have a working smoke alarm.
The majority of states require smoke alarms to be used in both new and existing homes, and more than 90 percent of homes have at least one. The early warnings these devices provide are a big reason why the nation's fire fatality rate has been dropping.
Unfortunately, many homes have alarms that aren't in working order, and the danger here is clear: Approximately 90 percent of child fire deaths occur in homes without working smoke alarms.
Tales from the Safety Zone
Some smoke detector history, courtesy of the National SAFE KIDS Campaign: In the 1920s, a merchant marine pumped air from below the ship's deck into a glass box. If the box turned dark, he knew there was a fire. Today's technology is based on a concept developed in the 1930s by a Swiss doctor who discovered that electricity can't pass through smokey air. His system set off an alarm when the air in a special chamber became smokey. Today's alarms activate when smoke breaks an electrical current or beam of light.
Some homes don't have enough smoke alarms or don't have them located properly. Smoke alarms should be on every level of your home and near the bedrooms—they have to be close enough to wake you in case a fire breaks out during the night. They should be installed on the ceiling or on the wall 6 to 12 inches below the ceiling.
If you have an alarm that gives frequent nuisance alarms—such as in the kitchen when you burn the toast or in the bathroom where steam can set it off—don't simply disconnect it. First, clean it according to the manufacturer's recommendations. If it still goes off, move it to a nearby location.
Smoke Alarm Maintenance
Batteries should be changed annually or when a chirping noise indicates the battery power is low. Test your alarms monthly.
The National Fire Protection Association recommends an alarm be replaced after 10 years even if the monthly tests indicate it is still working. Over that many years, smoke alarms lose sensitivity and eventually fail. A national study found that when they fail, they do so suddenly. Since alarms can be purchased for as little as $8, this is a small price to pay to make sure your alarm will save your life.
Smoke alarms should be kept clean. Accumulated dust, cobwebs, or insects can reduce the alarm's sensitivity. Vacuum them occasionally or follow the manufacturer's cleaning instructions.
Along with smoke alarms, every home should have carbon monoxide detectors to alert family members to this odorless, deadly gas that is emitted by poorly maintained furnaces and other fuel-burning appliances. See The Silent Killer: Carbon Monoxide.
What to Buy
There are two types of alarms: ionization and photoelectric. Ionization alarms are quicker at sensing flaming fires that have little smoke, and photoelectric ones are faster at detecting smoke from a smoldering fire such as one that starts slowly in upholstery. Either type provides adequate protection for homes. To be extra safe, some people buy both kinds or a combination unit. Whatever you buy, it should meet the standards of an independent testing laboratory such as Underwriters Laboratories (UL) and carry that label.
There also are differences in how alarms are powered. Most alarms are battery-operated, but some new homes have alarms that are hardwired into the electrical system. The hardwired ones can also be interconnected so that, if an alarm goes off in one part of the home, the others will sound, too. The national fire alarm code, the recognized industry standard, calls for hardwired and interconnected smoke alarms in newly constructed homes. Hardwired alarms should have battery back-up power so an electrical outage won't render them inoperable.