Ionisation alarms utilize a small amount of radioactive material called americium-241 in an ionising chamber – when smoke enters this chamber and lowers the electrical current the alarms sounds. Photoelectric alarms use a light beam – when that beam is interrupted the alarm will activate.
The most common type of smoke alarm installed in Australian homes is the ionisation alarm. This is largely due to the price, and can be commonly purchased for around $10. Ionisation alarms will not detect a fire effectively in its smoldering (early) stage. This stage of the fire is considered the most deadly due to the amount of toxic fumes being generated and filling the structure. Ionisation alarms are effective in detecting a flaming fire however this is often too late and fire development from this point is usually rapid. Ionisation alarms are sensitive to cooking fumes but not the products of combustion generated from modern furnishings and finishes that our homes are full of. Due to the amount of false alarms North West Smoke Alarms technicians often find that tenants have disabled ionization alarms by removing batteries. It is important to remember that an ionisation alarm is better than no alarm at all and can be used in combination with a photoelectric alarm.
Photoelectric smoke alarms will detect a smoldering fire in its early stages significantly earlier than an ionisation alarm and will more likely alert occupants in time for a safe escape. This is the position of the Australasian Fire and Emergencies Service Authorities Council (AFAC) since 2006. North West Smoke Alarms only install photoelectric smoke alarms.
North West Smoke Alarms are not in the business of scaremongering, nor are we trying to generate additional sales of photoelectric smoke alarms. The purpose of this page is to better inform our clients, tenants and the public on the importance of choosing the correct smoke detectors to adequately protect life and property.