There are many brands of smoke alarms on the market, but they fall under 2 basic types: ionization and photoelectric.

Ionization and photoelectric smoke alarms detect different types of fires. Since no one can predict what type of fire might start in their home, the U.S. Fire Administration recommends that every home and place where people sleep have:

Both ionization AND photoelectric smoke alarms, OR
Dual-sensor smoke alarms, which contain both ionization and photoelectric smoke sensors.

Choose interconnected smoke alarms so that when one sounds, they all sound.

There are also alarms for people with hearing loss. These alarms may have strobe lights that flash and/or vibrate to alert those who are unable to hear standard smoke alarms when they sound.

Smoke alarms are powered by battery or by your home's electrical system. If the smoke alarm is powered by battery, it runs on either a disposable 9-volt battery or a nonreplaceable 10-year lithium-ion (“long-life”) battery. Alarms that get power from your home's electrical system, or “hardwired” alarms, usually have a backup battery that will need to be replaced once a year.

• Install at least one in every floor including the basement and attic and inside each sleeping area.
• Ensure that all members of your family can hear the smoke alarm. If someone is hearing impaired, install alarms that flash a strobe light as well as sound an alarm.

• Follow the directions that are provided with the alarm.

Experts recommend that:

• Put smoke alarms inside and outside each bedroom and sleeping area. A closed door may slow the spread of smoke, heat and fire.
• Put alarms on every level of the home. Smoke alarms should be interconnected. When one sounds, they all sound.
• Put smoke alarms on the ceiling or high on the wall. Check the manufacturer's instructions for the best place for your alarm.
• Only qualified electricians should install hardwired smoke alarms.

Some fire departments will install battery-operated smoke alarms in your home at no cost. Contact your local fire department's nonemergency phone number for more information.

• Follow the directions that are provided with the alarm.

Experts state that:

• Most battery-powered smoke alarms can be installed by following the manufacturers instructions using a drill and screwdriver.
• Plug in alarms must have restraining devises so they cannot be unplugged by mistake.
• Hard-wire alarms need to be installed by a qualified electrician.
• Never connect a smoke alarm to a circuit that can be turned off from a wall switch.

Is your smoke alarm still working? A smoke alarm with a dead or missing battery is the same as having no smoke alarm at all. A smoke alarm only works when it is properly installed and regularly tested. Take care of your smoke alarms according to the manufacturer's instructions. Below are some general maintenance tips.

Smoke alarm powered by a 9-volt battery

• Test the alarm monthly.
• Replace the batteries at least once every year.
• Replace the entire smoke alarm every 10 years.

• Smoke alarm powered by a 10-year lithium-ion (or “long-life”) battery

• Test the alarm monthly.
• Replace the entire smoke alarm according to the manufacturer's instructions.

• Smoke alarm that is hardwired into your home's electrical system

• Test the alarm monthly.
• Replace the backup battery at least once every year.
• Replace the entire smoke alarm every 10 years.