Smoke Detectors


Smoke Alarms - What You Need to Know

 Smoke Alarms Save Lives

Smoke DetectorThe majority of fatal home fires happen at night when people are asleep. Contrary to popular belief, the smell of smoke may not wake a sleeping person. The poisonous gases and smoke produced by a fire can numb the senses and put you into a deeper sleep.

Inexpensive household smoke alarms sound an alarm, alerting you to a fire. By giving you time to escape, smoke alarms cut your risk of dying in a home fire nearly in half. Smoke alarms save so many lives that most states have laws requiring them in private homes.

Fire experts agree that 40 to 50 percent of the 6000 lives lost in residential fires in the country last year could have been saved if the families had used smoke detectors.

We’re pleased that you’ve taken the first step to making your horn. safer for your family by learning about smoke detectors and home fire safety.

 Why do I need a smoke detector in my home?

House burning

Most fire fatalities occur between 2am and 6am—when people are asleep and their natural “fire sensing equipment” is least effective. These deaths are caused by the inhalation of poisonous gases or smoke, which reach victims before the flames.

  Many suffocate without ever waking or even becoming aware of the fire. They die because they had no warning.

  A smoke detector can sense a fire and sound a alarm while there is time to escape safely.  



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 Choosing an Alarm

Be sure that the smoke alarms you buy carry the mark of an independent testing laboratory. Several types of alarms are available. Some run on batteries; others run on household current.  All approved smoke alarms, regardless of type, will offer adequate protection provided they are installed and maintained properly.

Tests conducted by the National Bureau of Standards showed ionization detectors to be slightly more effective in detecting flaming fires and photo electronic models are slightly more effective in detecting smoldering fires. Both offer effective protection.

For the best coverage of all types of fires, select one of each type or the combination ionization-photo electronic model.

A very important thing to look for in purchasing a detector of either type is a listing mark from a licensed testing laboratory. The Underwriters Laboratories (UL) listing will assure you of a quality product.

Many hardware stores, general merchandise stores and home improvement centers carry smoke detectors. If you are unsure where to buy them, call your local fire department for suggestions. Some fire departments offer smoke detectors for little or no charge. Do not purchase used smoke detectors. 

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 How does a smoke detector work?

Smoke Detector cut away viewSmoke detectors are designed to sense particles given off by a developing fire.

There are two types of residential fire detection sensing systems: the ionization type and the photo electronic type.

The ionization type detectors sound their alarm when tiny, invisible products of combustion enter the chamber where air has been ionized. These combustion particles interrupt the ionized current causing the loud alarm to sound.

Ionization detectors incorporating a bright stationary light are also available. This type of detector is designed to turn on its light when it goes into alarm, thereby providing illumination for an escape path or stairwell.

Photo electronic type detectors contain a light source whose beam is deflected into a photocell by smoke, sounding an alarm.

There are also new state-of-the-art detectors which combine the ionization and photo electronic sensing systems in one unit. These provide the optimum coverage for all types of fires.

Smoke detectors last about eight to ten years. like any other electrical device, these do wear out over time. To help remind you of when to replace them, use a marker to write the installation date on the inside of your detector. That way you will know when to replace it.

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 Is One Enough?

Every home should have a smoke alarm outside each sleeping area and on every level of the home, including the basement. The National Fire Alarm Code, developed by the National Fire Protection Association (NFPA), requires a smoke alarm in each sleeping room for new construction. On floors without bedrooms, alarms should be installed in or near living areas, such as dens, living rooms, or family rooms.

Be sure everyone sleeping in your home can hear your smoke alarms' alarm. If any residents are hearing impaired or sleep with bedroom doors closed, install additional alarms inside sleeping areas. There are specially designed detectors for the hard of hearing or hearing impaired. These devices use bright strobe lights and vibrating alarms for notification.

There are special smoke alarms for the hearing impaired; these flash a light in addition to sounding an audible alarm.

For extra protection, the NFPA suggests installing alarms in dining rooms, furnace rooms, utility rooms, and hallways. Smoke alarms are not recommended for kitchens, bathrooms, or garages - where cooking fumes, steam, or exhaust fumes could set off false alarms - or for attics and other unheated spaces where humidity and temperature changes might affect a alarm's operation.

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 Where to Install

Because smoke rises, mount alarms high on a wall or on the ceiling. Wall-mounted units should be mounted so that the top of the alarm is 4 to 12 inches (10 to 30 centimeters) from the ceiling. A ceiling-mounted alarm should be attached at least 4 inches (10 centimeters) from the nearest wall. In a room with a pitched ceiling, mount the alarm at or near the ceiling's highest point.

In stairways with no doors at the top or bottom, position smoke alarms anywhere in the path of smoke moving up the stairs. Always position smoke alarms at the bottom of closed stairways, such as those leading from the basement. Dead air trapped near the door at the top of a stairway could prevent smoke from reaching an alarm located at the top.Smoke detector placement graphic

Don't install a smoke alarm too near a window, door, or forced-air register where drafts could interfere with the alarm's operation.


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Installation and maintenance

Most battery-powered smoke alarms and alarms that plug into wall outlets can be installed using only a drill and a screwdriver by following the manufacturer's instructions. Plug-in alarms must have restraining devices so they cannot be unplugged by accident. Alarms can also be hard-wired into a building's electrical system. Hard-wired alarms should be installed by a qualified electrician. Never connect a smoke alarm to a circuit that can be turned off from a wall switch. If you are uncomfortable standing on a ladder, ask a friend or relative to help. Some fire departments will install a smoke detector in your home for you. Call your local fire department's non-emergency telephone number if you have problems, need advise or assistance.

Smoke detectors are relatively simple to maintain. Manufacturers recommend that the unit be tested once a week. This can be done by pressing the test button or blowing a small amount of pipe or cigarette smoke into the detector. A common tip for maintenance is to CHANGE YOUR BATTERY WHEN YOU CHANGE YOUR CLOCK. When you replace the battery, use a vacuum cleaner to pull any dirt, dust or debris that may be found underneath the detector cover.

Change your battery



Replace the battery every year in all battery operated smoke detectors. (The detector is designed to emit short “beeps” with increasing frequency when the battery is losing power).




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Other important considerations include:

 False Alarms

Cooking vapors and steam sometimes set off a smoke alarm. To correct this, try moving the alarm away from the immediate kitchen area and bathrooms.

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