Smoke Alarms

Smoke alarms are one of the least expensive safety features for our homes. A smoke alarm is required for each sleeping room, and within 10 feet outside the sleeping rooms. At least one smoke alarm should be installed on each level of the home.smoke alarm

Smoke alarms come in various shapes and sizes and are made by several different manufacturers. Dual purpose CO and smoke alarms are becoming very popular. With dual purpose alarms, three (3) beeps indicate a smoke alarm and four (4) beeps indicate a CO alarm.

Key points to ensure smoke alarms are effective:

  • Replace the battery at least annually. Daylight savings time is a good reminder.
  • Vacuum around the alarm to remove any dust that might have built up in the unit. A dusty or dirty alarm can cause false alarms. Canned air works as well. This should be done a few times during the year.
  • Replace smoke alarms that are older than 10 years.
  • Test each of the alarms monthly to ensure they are working properly.
  • When purchasing multiple smoke alarms for your home, make sure they are all the same brand.
  • Make sure your alarms are properly installed.
  • Identify escape routes in your home and practice using them.
  • Have a designated meeting area, outside, and make sure that everyone in your family knows where it is.. Too often firefighters get injured going inside a building looking for someone who isn't there because they were not at the designated meeting area.
  • Once outside the home, DO NOT go back in!

Types of Alarms

When purchasing a smoke alarm for your home, it is important to be aware that two types of smoke alarms are available to the public: Ionization and Photoelectric.

Ionization smoke alarm typically are better at detecting fast flaming fires, which consume combustible materials rapidly and spread quickly. Examples of fast flaming fires include paper burning in a wastebasket, or a grease fire in the kitchen.

Photoelectric smoke alarm generally are more effective on slow smoldering fires. These are fires that smolder for hours before bursting into flames, such as when a lighted cigarette is dropped onto a couch or bedding.

There also is a dual or double sensor alarm, which is effective at detecting both slow smoldering fires and flaming fires.


Photoelectric alarms and sensor alarms are usually more expensive than the most commonly used ionization alarm.

Battery Considerations

Batteries should be replaced twice a year. Performing this task when daylight savings time begins and ends is an easy way to remember to do it. A long-life battery, which lasts up to 10 years, is now available for smoke alarms. These batteries work best in newer smoke alarms. Be aware that a new long-life battery could actually outlive an older smoke alarm, giving people a false sense of security.


Smoke alarms need to be placed inside and outside of all bedrooms and on every level of a home. Placement in areas such as the kitchen or near the bathroom door may cause false alarms.

For more information about smoke alarms you can go to the Minnesota State Fire Marshal's website.