Smoke Alarm

Installing smoke alarms

Choose smoke alarms that have the label of a recognized testing laboratory.
Install smoke alarms inside each bedroom, outside each sleeping area and on every level of the home, including the basement.
On levels without bedrooms, install alarms in the living room (or den or family room) or near the stairway to the upper level, or in both locations.
Smoke alarms installed in the basement should be installed on the ceiling at the bottom of the stairs leading to the next level.
Smoke alarms should be installed at least 10 feet (3 meters) from a cooking appliance to minimize false alarms when cooking.
Mount smoke alarms high on walls or ceilings (remember, smoke rises). Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm).
If you have ceilings that are pitched, install the alarm within 3 feet of the peak but not within the apex of the peak (four inches down from the peak).

Figure A.29.8.3.1 from NFPA 72, National Fire Alarm and Signaling Code (2013 edition).
Don't install smoke alarms near windows, doors, or ducts where drafts might interfere with their operation.
Never paint smoke alarms. Paint, stickers, or other decorations could keep the alarms from working.
For the best protection, interconnect all smoke alarms. When one smoke alarm sounds they all sound. Interconnection can be done using hard-wiring or wireless technology.
When interconnected smoke alarms are installed, it is important that all of the alarms are from the same manufacturer. If the alarms are not compatible, they may not sound.
There are two types of smoke alarms – ionization and photoelectric. An ionization smoke alarm is generally more responsive to flaming fires, and a photoelectric smoke alarm is generally more responsive to smoldering fires. For the best protection, both types of alarms or combination ionization-photoelectric alarms, also known as dual sensor smoke alarms, are recommended.
Keep manufacturer’s instructions for reference.

Safety Tips

Share these life-saving tips with residents as you install new alarms for them or change the batteries in existing alarms.

• Once the alarm sounds, you may have as little as two minutes to escape.

• Test your smoke alarms once a month by pushing the test button.

• Smoke alarms with nonreplaceable (long-life) batteries are designed to remain effective for up to 10 years. If the alarm chirps, warning that the battery is low, replace the entire smoke alarm right away.

• For smoke alarms with any other type of battery, replace batteries at least once a year. If that alarm chirps, replace only the battery. Hint: schedule battery replacements for the same day you change your clocks from daylight saving time to standard time in the fall.

• Never “borrow” a battery from a smoke alarm. Smoke alarms can’t warn you of fire if the batteries are missing or have been disconnected.

• Don’t disable smoke alarms even temporarily. If your smoke alarm is sounding “nuisance alarms,” try relocating it further from the kitchen, where cooking fumes or steam can cause the alarm to sound. Or, replace the alarm with a photoelectric type alarm which is not as sensitive to cooking fumes.

• Follow the manufacturer’s instructions for cleaning to keep smoke alarms working well.

• Practice your home fire escape drill twice a year with everyone in your home. Practice at night and during the daytime. Practice your drill with overnight guests.

Smoke Alarm Installation and Maintenance

Alarm Placement

Smoke alarms should be installed according to NFPA 72 and the manufacturer’s instructions. Heat and smoke rise, so smoke alarms should be installed on the ceiling or high on a wall to detect the first traces of smoke.If a room has a pitched (slanted) ceiling, mount the unit near the ceiling’s highest point, 4 to 12 inches (10 to 30.5 centimeters) away from the wall. If the room has an A-frame ceiling, mount the unit at least 4 to 12 inches (10 to 30.5 centimeters) away from the peak.

Wall-mounted smoke alarms should be installed so that the top of the alarm is not more than 12 inches (30.5 centimeters) from the ceiling.Install basement smoke alarms close to the bottom of the stairs. Don’t install an alarm at the top of basement stairs; dead air trapped near the closed door could prevent smoke from reaching the unit.Some household environments can cause nuisance alarms or interfere with a smoke alarm’s operation. Avoid placing alarms near a cooking appliance, a dusty area, a shower, or any area where the temperature drops below 40°F (4.5°C) or rises above 110°F (43°C).

Cooking fumes, steam, and automobile exhaust can result in nuisance alarms. Do not install alarms in bathrooms, kitchens, garages, attics, or unheated areas or near recessed ceiling areas, ceiling fans, furnaces, or furnace vents. Place alarms at least 3 feet (0.9 meter) horizontally from bathroom doors.It’s a good idea to have an experienced installer available, if possible, while your volunteers are in the field. Give volunteers a phone number to call your expert for advice on installation problems.

Smoke Alarm Types and Features

Smoke alarms are available in a variety of types and features. These types and features are summarized below along with considerations for their application.

Power Systems

Many jurisdictions require new homes and multifamily dwellings to have smoke alarms hardwired into their electrical systems.
Conventional batteries: Models using replaceable batteries (only) should have their batteries replaced in accordance with the manufacturer’s instructions or whenever the low battery indicator sounds. Replace the batteries with the ones that are specifically listed for replacement by the smoke alarm manufacturer. The batteries specified are required to last at least one year. It is a good idea to replace standard alkaline batteries proactively once a year. (If lithium batteries are included in the list of batteries specified by the manufacturer, they will typically last much longer than a year.) These models – as with all smoke alarms – are required to have regular maintenance, including testing at least once a month.
Non-Replaceable Long-life batteries: Manufacturers have introduced smoke alarms with long-life non-replaceable batteries that last up to 10 years. Smoke alarms with non-replaceable long-life batteries offer an advantage for older people or people with disabilities who may have difficulty replacing batteries. (These alarms usually do not have the ability to be interconnected.) Alarms powered by long-life power cells still require regular testing and maintenance. The smoke alarms themselves need to be replaced after 10 years.
Hardwired smoke alarms: Hardwired alarm systems are powered by the home’s AC electrical system, which also allows the alarms to be interconnected—when one goes off, they all sound. Most hardwired alarms are required to have a battery back-up. Hardwired alarm systems should be tested at least monthly, but replacement should be done by a qualified contractor. The back-up battery should be replaced in accordance with the manufacturer’s instructions or whenever the low battery indicator sounds. There are now wireless interconnected smoke alarms available that are easier to install.

Low-Battery Warning Feature

All battery-powered alarms have a low-battery warning that “chirps” when battery power is low. Since the warning signal itself will stop after a few days, residents are encouraged to test their alarms after they’ve been away from home for several days. If the smoke alarm “chirps” signaling a low battery, replace the battery right away.

Sensing Systems

Most smoke alarms use one of two common sensing systems for detecting a fire. Ionization-type smoke alarms pass an electric current through a “sensing chamber.” When smoke enters the chamber, it reduces the flow of current and activates the alarms. An ionization smoke alarm is generally more responsive to flaming fires. Photoelectric-type smoke alarms aim a light source into a sensing chamber. Smoke enters the chamber and reflects light onto the light sensor, triggering the alarm. A photoelectric smoke alarm is generally more responsive to smoldering fires. For the best protection, both types of alarms or combination ionization-photoelectric alarms, also known as dual-sensor smoke alarms, should be installed.

Other Smoke Alarm Features

Manufacturers are offering smoke alarms with new consumer features, some of which are especially appropriate for older adults. Take these options into account when buying alarms for your community installation project, but be sure that any alarm you purchase bears the label of a recognized testing laboratory.

Hush buttons: Nuisance alarms resulting from a smoky oven, burned toast, or other non-threatening circumstance are a common complaint. If cooking fumes or steam sets off nuisance alarms, replace the alarm with an alarm that has a “hush” button. A hush button will reduce the alarm’s sensitivity for a short period of time. An ionization alarm with a hush button or a photoelectric alarm should be used if the alarm is within 20 feet of a cooking appliance. Pressing the hush button deactivates the alarm for roughly 7 minutes, after which it reactivates automatically. If a real fire occurs, the unit will override the pause feature and sound the alarm. Missing or disconnected batteries are the leading cause of smoke alarm failure. The hush feature discourages the dangerous (and too common) practice of disconnecting or removing alarm batteries in response to nuisance alarms and is recommended for use in all locations.
Voice capability: Some smoke alarms may also be designed with either a pre-recorded voice message or the ability to record voice messages during certain portions of the alarm signal. This feature helps to reinforce the alarm’s urgency and, where capable, can be used by parents to record a message in a voice more recognizable to their children.
Escape Light: Some smoke alarms are available with a built-in safety or escape light. When the smoke alarm sounds, the light is also activated, helping you to exit the area.
Easy-to-install battery mounts: Standard 9-volt batteries used in many smoke alarms require the consumer to snap the battery’s terminals into tight-fitting connectors, which may be difficult for some older adults.
Alarms with spring-metal terminal contacts reduce the difficulty of installing batteries but increase the potential for installing a battery backwards (switching positive and negative terminals). Residents should be cautioned to properly align the battery terminals with the polarity symbols (+ and -) on the alarm’s battery mount.
Convenient test buttons: Some smoke alarms are equipped with a large, rectangular, easy-to-push test button. These may be attractive to consumers who are unable to or reluctant to stand on ladders.

Life Span

Smoke alarms should be replaced when they are 10 years old. Immediately replace a smoke alarm that does not respond when tested, even after you have replaced the battery.

Training Tips

Installing smoke alarms

A successful installation program involves making sure that alarms are installed correctly and in the right locations.

• Install smoke alarms in every bedroom, outside each separate sleeping area, and on every level of the home, including the basement. Larger homes may require additional smoke alarms to provide a minimum level of protection.

• For the best protection, interconnect all smoke alarms, so when one sounds, they all sound.

• If someone in the home has profound hearing loss, install alarms with high intensity strobe lights. Vibration equipment is required and is activated by the sound of the alarm.

• If someone in the home is hard of hearing, a complex, low-frequency audible signal works best. A separate device that is activated by the sound of the alarm is available.

• Mount smoke alarms high on walls or ceilings (remember, smoke rises).

• If you have ceilings that are pitched, install the alarm near the ceiling’s highest point.

• Don’t install smoke alarms near windows, doors, or ducts where drafts might interfere with their operation.• Smoke alarms should not be installed in attics, bathrooms, or garages.

• Install smoke alarms away from the kitchen to prevent false alarms. Generally, they should be at least 10 feet from a cooking appliance.

Installing smoke alarms

Testing smoke alarms