Ionization & Photoelectric Alarms
There are many different brands of smoke alarms available on the market, but they fall under two basic types: ionization and photoelectric.
It cannot be stated definitively that one is better than the other in every fire situation that could arise in a residence. Because both ionization and photoelectric smoke alarms are better at detecting distinctly different, yet potentially fatal fires, and because no one can predict what type of fire might start in a home, the USFA recommends that every residence and place where people sleep be equipped with both ionization and photoelectric smoke alarms, or dual sensor smoke alarms, which contain both ionization and photoelectric smoke sensors
Hearing Disability Alarms
In addition to the basic types of alarms, there are alarms made to meet the needs of people with hearing disabilities. These alarms may use strobe lights that flash and/or vibrate to assist in alerting those who are unable to hear standard smoke alarms when they sound.