The Two Main Smoke Alarm Types

Combination Smoke and CO Alarm 147083364There are two main smoke alarm types that homeowners can choose between for their home security and fire escape plan. These are the Ionization smoke alarm and the Photoelectric smoke alarm. One is not better than the other in every circumstance; each has strengths that are particularly useful in distinguishing and detecting certain types of fires. Each of these types of smoke alarms will be described in detail below.

Ionization Smoke Alarms

Ionization smoke alarms are generally better at detecting flaming fires that arise in the house. Inside them are two plates that are electrically charged which hold between them a tiny bit of radioactive material, specifically americium-241. Through this radioactive material the air between the electrically charged plates is ionized and a current flows between them. Then, when smoke comes, the ion flow is disturbed and the current is decreased. The result is the alarm being activated. These are the most common house alarms, very affordable, and they react very quickly to flaming fires. If there’s an event of a kitchen fire from a pan of grease on the stove or a trash can on fire from a lit match, an ionization alarm will react quickly. However, it will be slower to respond to smoldering fires that come up.

Photoelectric Smoke Alarms

Photoelectric smoke alarms, on the other hand, respond better to smoldering fires in the house like one caused by a cigarette on the carpet or couch. Basically, photoelectric smoke alarms are made with both a sensor and a light inside them, set at 90 degree angles from each other. The light normally is directed straight across the way and does not touch the sensor. Blue house outline 164724113However, when there is smoke in the air, the particles of smoke will scatter the particles of light so that some of them will touch the sensor. This will set the alarm off. Though a bit more expensive, these may be even more useful than ionization smoke alarms because the fires they sense are often ones that you don’t catch on your own (like grease fires).


You can purchase combination alarms called dual sensor smoke alarms that have both ionization and photoelectric sensitivity within them. These kinds of alarms are not so common, however. It has been recommended by the United States Fire Administration that both kinds of alarms are installed in every home. In this way, you can combat several different varieties of house fires that may arise by making sure that you have sensors that are made specially to detect them. With both kinds of alarms, you can use the home electrical wiring to power them or you can use batteries to run them.

With house fires happening every ten seconds in homes across America, smoke alarms are desperately needed. And with deaths occurring every two and a half hours from house fires, they may end up saving the lives of you and your family. When choosing the smoke alarms for your home, install some of each of these smoke alarm types to make certain your home is securely cared for and monitored.