There are many brands and models of smoke alarms, but the most common types include:

• Ionization alarms are generally more responsive to fast-moving, flaming fires.
• Photoelectric alarms are generally more responsive to slow, smoldering fires that produce a lot of smoke.
• Dual-sensor alarms combine both ionization and photoelectric technologies in a single alarm.
• Alarms for people who are deaf or hard of hearing may include flashing strobe lights, bed or pillow shakers, or other alerting devices in addition to an audible alarm.

When choosing a smoke alarm, look for one that is listed by a recognized testing laboratory and follow the manufacturer's instructions for installation, testing, and replacement.

Smoke alarms should be installed:

• Inside every bedroom
• Outside each sleeping area
• On every level of the home, including the basement

Install smoke alarms on the ceiling or high on a wall, following the manufacturer's instructions for proper placement. Properly placed alarms help provide the earliest possible warning when smoke is detected.

For the best protection, smoke alarms should be interconnected so that when one alarm sounds, they all sound.

Hardwired alarms are connected to your home's electrical system and should be installed and maintained by a qualified electrician. Wireless interconnected alarms communicate with each other without requiring additional wiring and can be a good option for existing homes.

Many battery-operated smoke alarms can be installed using basic household tools. Always follow the manufacturer's instructions for proper installation, placement, testing, and maintenance.

Smoke alarms should generally be replaced every 10 years. Check the manufacture date on the back of the alarm and follow the manufacturer's recommendations for replacement.

If your alarm is not working properly or continues to chirp after replacing the battery, it may need to be replaced sooner.

Smoke alarms may use replaceable batteries or a sealed, long-life battery, depending on the model.

• Replaceable batteries: Some alarms use 9-volt, AA, or AAA batteries. Replace the batteries according to the manufacturer's instructions or whenever the alarm indicates the battery is low.
• Sealed 10-year batteries: Many newer smoke alarms have a built-in lithium battery designed to last for the life of the alarm. The battery cannot be replaced, so the entire alarm must be replaced when it reaches the end of its life.
• Hardwired alarms: Alarms connected to your home's electrical system typically have a backup battery. The type of battery and replacement schedule will depend on the alarm.

Regardless of the type of battery, test your smoke alarms regularly and follow the manufacturer's instructions for maintenance and replacement.