More than 95 percent of U.S. homes have at least one smoke detector installed inside them, but most homeowners remain unaware of the different kinds of sensors available and their effectiveness, reports the U.S National Fire Protection Association.
In fact, there are two main types of smoke detector sold in the U.S.: ionization and photoelectric.
Ionization smoke detectors are by far the most common, accounting for around 90 percent of all such devices sold in the U.S.
But the National Fire Protection Association warns that these ionization smoke detectors are the least effective of the two, as they’re not as quick at detecting slow-burning or smoldering fires. Unfortunately these types of fires are the most common in people’s homes, caused by discarded cigarette butts, electrical wires and fireplace embers. By the time these alarms detect a fire, it’s likely that the smoke and carbon dioxide levels are already at a dangerous level.
Joseph Fleming, deputy fire chief at the Boston Fire Department, says that ionization smoke detectors could be responsible for up to 30,000 deaths since 1990.
The problem is that ionization smoke detectors are much more common because they cost around half the price of a photoelectric-based alarm, and have longer battery lives.
Even so, a study by the National Institute of Standards and Technology shows that a photoelectric smoke detector is able to detect smoke between 20 and 50 minutes faster than an ionization detector. As such, some states, including Massachusetts, Maine and Vermont, have brought in laws making it mandatory for new residential homes to have photoelectric smoke detectors installed.
Experts say photoelectric smoke alarms may be a wise investment to install in bedrooms and hallways. Ionization smoke alarms can be suitable for the kitchen, however.