Ionization vs. Photoelectric Smoke Alarms

Smoke alarms help provide an early warning to a smoke or fire emergency, but did you know there are two types of smoke alarms? Photoelectric smoke alarms are generally more sensitive to detecting smoke from smoldering fires, while ionization smoke alarms are generally more sensitive to smoke from fast, flaming fires. All fires produce smoke particles in varying number and size, so it is important to understand the different types of smoke sensing technology to help protect your home and family.

Ionization Smoke Alarms

Ionization sensing technology is generally more sensitive than photoelectric sensing technology at detecting small particles, which tend to be produced in greater amounts by flaming fires. These types of fires consume combustible materials rapidly and spread quickly. Sources of fast, flaming fires may include paper burning in a wastebasket or a grease fire in the kitchen.

Photoelectric Smoke Alarms

Photoelectric sensing technology is generally more sensitive than ionization sensing technology at detecting large particles, which tend to be produced in greater amounts by smoldering fires. These types of fires may smolder for hours before bursting into flame. Sources of smoldering fires may include cigarettes burning in couches or bedding.

Install Both Sensing Technologies for Maximum Protection

For maximum protection, install both types of smoke alarms on each level and in every bedroom of your home. First Alert offers a variety of ionization and photoelectric smoke alarms including battery operated, hardwired and combination smoke and carbon monoxide alarms. For both types of sensors in one alarm, install dual sensor smoke alarms that use both sensing technologies. To identify if you have an ionization, photoelectric or dual sensor smoke alarm, review the packaging or back of the alarm to find the smoke sensor symbol. You will see one of the below: