A research review identified some important differences in the performance of different types of smoke alarms.
Conducted by Victoria University for the Bushfire CRC and the CRC’s fire agency partners, the review found that the photoelectric type of domestic smoke alarm is more effective than the more common ionisation type of alarm at detecting smouldering fires in houses.
There are two common types of smoke alarms in Australia that operate on different principles – the ionisation detector responds by analysing the smoke in the air, the photoelectric detector uses a light beam to detect the airborne smoke.
The ionisation detector is the more common of the two and is generally cheaper and more readily available in shops.
The research review concludes that ionisation detectors respond faster to flaming fires while photoelectric detectors respond faster to smouldering fires. However, while the photoelectric detectors responded to flaming fires in sufficient time to allow residents to safely react, the reverse may not be true.
It was found that ionisation detectors may not reliably respond to smouldering fires in all instances in enough time to allow for safe egress. In fact, it was fairly consistently found that they will not.