What is the difference between photoelectric and Ionization smoke alarms?

Ionization Smoke Alarms are generally more effective at detecting flaming fires, which consume combustibles quickly and spread rapidly. Sources of these fires include paper burning in a wastebasket, or grease fires on a stove. Photoelectric Smoke Alarms are generally more effective at detecting smoldering fires, which smolder for hours before bursting into flame. Sources of the fires include cigarette smoldering in couches or bedding. For maximum protection, install both types of smoke alarms on every level of your home.

There are generally two types of smoke detectors - ionization smoke detectors and photoelectric type smoke detectors. Smoke particles of a varying number and size are produced in all fires. Ionization technology smoke detectors are generally more sensitive than photoelectric technology smoke detectors at sensing small particles, which tend to be produced in greater amounts by hot, flaming fires, that are consuming combustible materials rapidly and may spread quickly. Sources of these fires may include paper burning in a wastebasket, or a grease fire in the kitchen.Photoelectric smoke detector technology is generally more sensitive than ionization smoke detector technology at sensing large smoke particles, which tend to be produced in greater amounts by smoldering fires, which may smolder for hours before bursting into flame. Sources of these fires may include cigarettes burning in couches or bedding.For maximum protection, use both types of technology on each level and in every bedroom of your home.