There are two types of smoke alarms: photoelectric and ionization. Depending on where the smoke originated, one type of alarm will give a quicker warning than the other. Are you aware of which type of smoke alarms are installed in your home? Learn the difference between photoelectric and ionization smoke alarms and why both should be installed in your home.
Ionization Smoke Alarms
- These alarms respond quicker to flaming fires which are fires that produce high amounts of heat.
- One example is when a candle tiptoes over and ignites curtains.
- Ionization smoke alarms are best used in rooms with highly flammable items such as grease, paint, or papers.
- Smoke alarms that are ionization-type have a small amount radioactive material (Americium-241) interconnected by two electrically charged plates. The alarm is activated when smoke enters the chamber.
Photoelectric Smoke Alarms
- Photoelectric smoke alarms respond quicker to smoldering flames. This means that fires that burn slowly and produce less heat are more effective.
- A cigarette can catch on to a cushion and create a fire. The smoke from smoldering fires can fill your home with tons of smoke before the flames emerge.
- The mechanism used to detect smoke in photoelectric smoke alarms is different. Smoke alarm chambers have a light that is reflected onto the light sensor and activates the alarm sound.
You can use both photoelectric smoke alarms and ionization in your home
- Both types of smoke alarms offer advantages in that both smoldering and flaming fires are possible in your home.
- Although an ionization alarm can detect a burning fire, it will take longer than a photoelectric one. To receive the most timely warnings, you should use both ionization alarms and photoelectric smoke alarms.
- Install separate photoelectric alarms if you have ionization fire alarms in your house. Check your owner’s manual to find out which alarms you have. You can also try this: Take the smoke alarm down, and examine the back. Look for “Photoelectric”, “Ionization”, “P” and “I”.
- Alternativly, you can replace existing alarms by combination alarms that combine both technologies into one device.
- Smoke alarms should be installed in all bedrooms, as well as outside of each sleeping area (including the basement) and on every floor of the house.
