Smoke detectors are an inexpensive addition to your home and provide the priceless value of protecting your family against possible fires. Our customers at Dean’s Home Services often have questions about smoke detectors. We’ve got all the answers here for everything you need to know about your smoke detector.
Are Smoke Detectors Required?
In Minnesota, homes are required by law to have smoke alarms located in each sleeping room, immediately outside each sleeping room and on each additional story, including basements and habitable attics. This applies to single-family homes, townhomes, apartments, hotels, lodging houses, and similar occupancies.
How Do Smoke Detectors Work?
Smoke detectors function in a few different ways:
- Ionization smoke detectors have a small bit of radioactive material set up an electric current inside the detector. When smoke enters the detector, it changes the electrical charge of the air molecules inside, causing the alarm to go off.
- Photoelectric smoke detectors use a beam of light in an optical chamber to detect smoke. When the smoke comes into the chamber, it causes the light to scatter. The light strikes the sensor in the smoke detector and causes the alarm to go off.
These smoke detectors react to different types of fires. The ionization alarm works best when the fire has not only started but is raging and quickly spreading. The photoelectric sensor works best when the fire is still smoldering and slow. Fortunately, there are smoke detectors that have both of these systems. The National Fire Protection Association recommends these alarms.
Where Should You Put Your Smoke Alarm?
Put your smoke alarm on the ceiling of every floor in the house to keep your family safe and your home up to code, especially:
- On each floor
- Outside every sleeping area
- Inside every bedroom
When Should You Change the Battery?
New homes are now required to have smoke detectors that are hard-wired into the electrical system with back-up batteries in case the power goes out. If you live in an older home, you should change your battery once a year. Many smoke detectors have a low battery warning light, and some smoke detectors start to chirp, annoyingly, when the battery is low.
It’s also a good idea to test the smoke detector every month. The unit will have a “test” button on it. If you press it and nothing happens, you may have a dead battery. Put in a fresh battery, and press the “test” button again. If it still doesn’t work, you may have a dead unit. Smoke alarms are best replaced every decade or so.