Smoke Alarms

One of the most important fire safety devices for the home is the smoke alarm. After becoming generally available in the early 1970's home smoke alarm sales grew rapidly and the price fell, so that by 1991, 88% of US homes had at least one.

 Several studies have concluded that when working smoke alarms are present, the chance of dying from the fire is cut in half. The smoke alarms currently in place have saved thousands of lives, but several problems exist. First, the 12% of homes without alarms have more than half of the fires; second, it is estimated that a third of the smoke alarms in place are not working, often due to failure to replace a worn out battery; and third, many homes do not have as many smoke alarms as are needed to protect the occupants properly. In this section, we will examine how to protect your family with smoke alarms.

How Many Alarms are Needed?

The primary job of our smoke alarm is to protect you from fires while you are asleep. Thus, your alarms should be located between any sleeping persons and the rest of the houses outside bedrooms or sleeping areas. But tests conducted in the 1970's clearly showed that this might not be enough.

In multi-story homes, fires on a floor level without a smoke alarm can grow too dangerous conditions before sufficient smoke can rise in a stairway to set off an alarm on the upper floor. Based on this observation, most codes require that additional smoke alarms be located on each floor level of the home.

A closed door provides protection from smoke on the other side, but will also prevent smoke from reaching a smoke alarm. This is particularly a problem in bedrooms. If you sleep with your bedroom door closed, you should add a smoke alarm in the bedroom; particularly if you smoke in the bedroom or there is a TV, air conditioner, or other major appliances in the bedroom that might start a fire. If you sleep with the bedroom door open, the alarm in the hall outside will detect a fire in the bedroom or elsewhere.

There are a few places where a smoke alarm should not be placed. These include kitchens and garages (cooking fumes and car exhaust are likely to set them off) and unheated attics and crawl spaces (where it can get too cold or hot for the electronics to work properly). Fires beginning in these areas are generally detected by the other smoke alarms in enough time to escape safely. If an alarm is desired in these spaces, heat detectors are available. But remember that the smoke alarms are the primary safety devices in any home protection scheme.

What Kind of Smoke Alarm Should You Get?

There are two types of home smoke alarms available; the ion type and the photoelectric type. The ion type reacts faster to open flaming fires and is usually the least expensive. The photoelectric type reacts faster to smoldering fires and is less likely to react to cooking. Both types provide good protection and can be used without worry. If you need more than one alarm, you might get one of each. There are also multiple ways to power smoke alarms. Most smoke alarms operate on a battery (usually 9 volt), which should be replaced at least once a year. When the battery needs changing, the smoke alarm will begin to "chirp" every 20 seconds or so, this will persist for a month. This is most likely to start in the middle of the night (when the temperature in the house drops) causing you to get up and remove the battery so you can sleep. To prevent this nuisance you should pick a special day and give your alarms new batteries once a year. Some fire safety organizations promote "change your clocks, change your batteries" when the change is made back from daylight savings time each fall. Always make sure that you use the right battery. The required battery type is marked on the alarm near where the battery goes. Smoke alarms installed in a house may be operated from the household electrical power and not need battery replacement. This type of alarm has a "power on" light to tell you that the alarm has power. Smoke alarms are available which run on house power but also have a battery in case the main power fails. Both types of alarms need to be tested monthly and batteries should be replaced yearly just as with the battery-only operated type.

How Should it be Installed?

Smoke alarms are normally installed on the ceiling or high on the wall, with the top of the alarm not closer than 4 inches nor further than 12 inches from the ceiling. Alarms should be no closer than 3 feet from supply registers of forced air heating systems (that might blow on the alarm preventing it from seeing smoke) and no closer than 3 feet from the door to a kitchen or a bathroom containing a shower (steam can set the alarm off when the door is opened).

If an alarm is mounted on an exterior wall or a ceiling below an unheated attic that is poorly insulated (the surface gets noticeably cold in the winter and warm in the summer), the temperature difference can prevent smoke from getting to the alarm. Placing the alarm on an inside wall avoids the problem. In desert climates where evaporative coolers are being used, mount smoke alarms on walls 12 inches below the ceiling. These coolers add moisture that can cause the smoke to drop.

Older adults may have difficulty reaching alarms on the ceiling to change batteries. If hard-wired alarms are impractical, wall mounting 12 inches down should be considered.

How Long Should Your Smoke Alarm Last?

Smoke alarms have a useful life of about ten years. At that age they should be replaced, even if they seem to be working. This will assure that the alarm will be working when you need it.

Even though prices of today's smoke alarms are less expensive than you might have paid some years ago, today's alarms are more reliable. Thus, it is usually not worth keeping an old alarm rather than buying a replacement.

Fire Safety Walk Through

• Keep clothes, blankets, curtains, towels and other items that can be easily set on fire at least three feet from space heaters, and away from stove burners.

• Place space heaters where they will not tip over easily.

• Have chimneys cleaned and inspected annually by a professional.

• Clear away trash, flammables and decorative materials.

• Always use a metal mesh screen with fireplaces and leave glass doors open while burning a fire.

• Never leave cooking unattended.

• Be sure your stove and small appliances are off before going to bed.

• Check for worn wires and do not run cords under rugs or furniture.

• Never overload electrical sockets.

• Keep lighters and matches out of the reach of children.

• Never leave cigarettes unattended and never smoke in bed.

• Make sure cigarettes and ashes are out. The cigarette needs to be completely stubbed out in the ashtray or run under water.

Taken in part from the US Fire Administration website.

About the U.S. Fire Administration (USFA)

As an entity of the Department of Homeland Security's Federal Emergency Management Agency, the mission of the USFA is provide national leadership to foster a solid foundation for our fire and emergency services stakeholders in prevention, preparedness, and response.

 www.BradleyElectricInc.com