Cons of Ionization Smoke Detectors Prone to False Alarms: Ionization detectors are notorious for their sensitivity. This can often lead to false alarms. Ionization detectors can also be triggered by cooking smoke or steam from the shower.
An ionization detector can quickly sense fast-moving fires, but has huge shortcomings in detecting smoldering, slow moving fires; such fires can go completely undetected by an ionization alarm.
Although ionization smoke detector has more advavantages compared to photoelectric smoke detector it is now being discontinued. The reason is that it contains radio active material. If you already have one that you need to replace, you are required to dispose it properly.
An ionization smoke alarm is generally more responsive to flaming fires (imagine a fire where you can see the flame), while a photoelectric smoke alarm is generally more responsive to smoking, smoldering fires (such as a cigarette).
Optical smoke detectors may respond slightly slower to fast, flaming fires compared to ionisation detectors. While they are excellent for smouldering fires, their response time might be marginally delayed in situations where rapid flame detection is crucial.
Since no one can predict what type of fire might start in their home, the U.S. Fire Administration recommends that every home and place where people sleep have: Both ionization AND photoelectric smoke alarms, OR. Dual-sensor smoke alarms, which contain both ionization and photoelectric smoke sensors.
“The probability of a fatality due to the failure of the photoelectric detector to detect a smoldering ignition fire is 4.06%. The probability of a fatality due to the failure of an ionization detector to detect a smoldering ignition fire is 55.8% …
Cons of Ionization Smoke Detectors
Prone to False Alarms: Ionization detectors are notorious for their sensitivity. This can often lead to false alarms. Ionization detectors can also be triggered by cooking smoke or steam from the shower.
Ionization models are best suited for rooms that contain highly combustible materials that can create flaming fires. These types of materials include flammable liquids, newspapers, and paint cleaning solutions. Photoelectric models are best suited for living rooms, bedrooms and kitchens.
Install a least one on every level of the home, including the basement. Place a smoke detector in every sleeping area. Ensure a smoke alarm is outside of every room, like in a hallway. If you have a level without a bedroom, install a detector in the living room, or near the stairway leading upstairs or downstairs.
The researchers concluded that ionization smoke alarms were poor at detecting smoke from smoldering fires; that many fires begin as smoldering fires before transitioning into flaming fires; therefore by the time an ionization detector goes into alarm the occupants could already be dead.
Please note: Ionisation smoke alarms are now being phased out across the entire fire safety industry in favour of optical smoke alarms due to manufacturing, transportation, and disposal concerns around the radioactive material that ionisation smoke sensors rely on. Why are ionisation smoke detectors being phased out?
Most detectors are certified for a useful life of ten years. Check the expiration date on your smoke detector when you replace the batteries. Throw away outdated ionization smoke detectors. Your community may have a separate recycling program for them.
For example, sudden changes in temperature can disrupt the ionization process and trigger an alarm. This is especially common in homes with central heating and air conditioning, where the temperature can fluctuate throughout the day. Malfunctioning sensors or other components can also cause false alarms.
Ionisation detectors contain a very small amount of a radioactive element called Americium 241 (so small it is not harmful to humans), the element causes air molecules to form a small electric current inside the chamber of the detector.
Potential for False Positives in Dusty Environments
While photoelectric detectors are generally less prone to false alarms, they can still be triggered in dusty environments. Particulate matter in the air, such as dust or insect debris, may scatter light and lead to false positives.
For best protection, it is recommended both (ionization and photoelectric) technologies be used in homes. In addition to individual ionization and photoelectric alarms, combination alarms that include both technologies in a single device are available.
Detectors with multiple sensor types (dual-sensor or multicriteria detectors) are typically better at alerting you to both flaming and smoldering fires. Ionization smoke detectors are best at detecting the small particles typical of fast, flaming fires, but they're poor at detecting smoky, smoldering fires.
Test smoke alarms every month by pressing their test buttons. If your alarms use regular batteries, swap in fresh batteries at least once a year. A “chirping” sound means that it's time to change batteries. Because alarm sensors wear out, replace each alarm at least every 10 years.
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.
Ionization alarms have about a 55% failure rate to save people in home fires.
Curie Environmental Services explains that California classifies smoke detectors as Universal Waste Electronic Devices due to their circuit boards and should not be put in the trash. (Curie also provides prepaid mail-in recycling services for ionization smoke detectors.) EZ On the Earth, a Simi Valley, Calif.
The main limitation associated with flame ionization detectors is that they are only sensitive to organic compounds that can be burned in the flame. Inorganic compounds can not be detected by FID analysis.
During fast-flame fires, ionization alarms failed to provide sufficient egress time more frequently than photoelectric alarms failed to do so. Ionization alarms are responsible for 97% of “nuisance alarms” – false alarms – and are thus much more likely to be disabled all together than other types of smoke alarms.