There are different types of smoke alarms that work in different ways. Because some alarms are more easily triggered by smoke than others, you need to know how an alarm is designed so that you place it in the appropriate location in your home.
Generally, you need more than one type of smoke alarm to keep your family safe. With an average of seven people in the U.S. dying every day in residential fires, it's important to know how the different technologies of alarms work so that you and your family get adequate warning of a fire and have enough time to escape.
How Photoelectric Alarms Work
A photoelectric, or optical alarm, contains an infrared LED inside the sensor chamber that triggers the alarm when smoke particles enter. The alarm detects larger smoke particles from small smoldering fires like those that often start in sofas or mattresses. You can place this particular type of smoke alarm outside bedrooms, in hallways and stairway landings, and near the kitchen, as the alarm won't be easily triggered by smoke from cooking and exhaust fumes.
How Ionization Alarms Work
Although ionization alarms are cheaper than photoelectric smoke alarms, that's not why you should buy them. An ionization alarm detects small particles of smoke that a fast-flaming fire produces. The alarm can even detect particles of smoke that are too small for you to see.
Since they are triggered more easily, you should not place an ionization alarm too near the kitchen or near bathrooms or the laundry room where steam can set them off. When smoke or steam changes the balance of the current inside the chamber, the alarm sounds.
To know whether you are buying an ionization or photoelectric smoke alarm, look on the bottom or back of the packaging. The manufacturer lists the symbol "I" or ionization or the symbol "P" or photoelectric. If you still aren't certain which type of smoke alarms to place in the different locations throughout your home, consider installing dual-sensor smoke alarms. These alarms combine ionization and photoelectric technologies; therefore, the alarms can detect both flaming and smoldering fires.
How Heat Alarms Work
Heat alarms detect heat rather than smoke and go off when the temperature in the sensor chamber reaches a certain degree. While this type of alarm is not as susceptible to false alarms like ionization alarms are, they respond more slowly. As a result, a fire usually is well established before the alarm sounds. If you are looking to avoid false alarms in your kitchen and garage where there can be smoke or exhaust in the air, a heat alarm is an option, although you won't get as early of a warning when there is a fire.
For more information, talk to a local smoke alarm dealer (like GMW Fire Protection) for a personalized plan for your home.