Wired or Battery Operated
Wired smoke alarms are wired to and powered from the electricity in your home while battery-operated smoke alarms are not wired to your homes electricity but are powered instead by a battery (usually 9-volt type).
When smoke alarms first became available for homes, the battery-operated type were the most common; however, once the wired in option was developed, they were thought to be safer. This was because they were not dependent on human intervention to maintain batteries and they could be interconnected so that when one smoke alarm sounded they all sounded. The problem was that they provided no protection during a power outage, thus, having both types (wired and battery operated) provided the best protection.
Technology has come a long way though; modern wired smoke alarms have back-up battery protection built right into them and battery-operated smoke alarms can be wirelessly interconnected. Many types even offer a 10-year battery that doesn’t need changing for the life of the smoke alarm.
Ionization | Photoelectric | Dual | Smart Laser
Do you ever wonder why some smoke alarms go off whenever someone takes a shower, or cooks, even if they’re not burning anything? These alarms are referred to as “nuisance alarms” and are one of the main drivers behind the requirement for the “hush” button built into modern smoke alarms.
In some homes, floor plans are such that it is difficult to place a smoke alarm between each sleeping area and the remainder of the home while at the same time keeping it far enough away from the kitchen or bathroom to avoid nuisance alarms. This is where photoelectric smoke alarms are preferred as they are less susceptible to false alarms. Photoelectric-type alarms respond first to slow smouldering fires. They aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.
Ionization smoke alarms on the other hand are generally more responsive to flaming fires. They have a small amount of radioactive material between two electrically charged plates, which ionizes or electrically charges the air molecules causing current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, reduces the flow of current and activates the alarm.
You can also purchase “dual sensor” or “combo” smoke alarms which incorporate both photoelectric and ionization technology all in one smoke alarm. Dual sensor smoke alarms respond quickly to both smouldering and flaming fires. If you are considering installing dual sensor smoke alarms keep in mind that, if you’re having problems with nuisance alarms you should install “photoelectric only smoke alarms” in those areas of your home you’re experiencing the false alarms, not duals.
Recently, newer technology introduced “smart laser” smoke alarms. Laser detection is similar to photoelectric technology; it works on the same light-scattering principle, but with 100x greater sensitivity. This makes the smart laser smoke alarm much better at distinguishing the difference between a smoke condition in your home and dust, moisture, or small insects thus reducing false alarms even further.
• Devices for Heavy Sleepers and/or Persons with Hearing Impairments
It is strongly recommended that you have your smoke alarms tested at night, when you are sleeping. The only sure way to know whether you will or will not awaken to the sound of you smoke alarms is by having someone test your smoke alarms when you are in a deep sleep. You cannot escape if you’re not awake!
If you cannot hear your smoke alarms when you are sleeping, talk to a hearing specialist to find out which of the following options, or combination of options, best meet your needs:
For more information on devices for persons with hearing impairments, please contact our Fire Prevention Division email@example.com or by calling 311.
Where to Install:
Always follow (and keep) the manufacturer’s instructions for installing your smoke alarms. For the best protection interconnected smoke alarms should be installed in every bedroom, outside each sleeping area, and on every floor, including the basement.
Test your smoke alarms every month by pressing and holding the test button for a few seconds. The alarm on the smoke alarm you are testing should sound within a few seconds and, any interconnected smoke alarms should sound within a few additional seconds of the alarm of the tested smoke alarm.
Always follow the manufacturer’s instructions when installing, testing, maintaining and replacing your smoke alarms.