What the law requires of any smoke alarm
Every alarm must be photoelectric, marked with Australian Standard 3786-2014, with no ionisation sensor. It must be less than 10 years old, work when tested and be interconnected with the other alarms, and it must be hardwired or run on a sealed 10-year battery.
Any brand that meets those points is legal. Which one you fit is a choice, and it affects how often the system goes off for no reason.
What we look for inside the alarm
Open two alarms side by side and the difference is on the circuit board. The alarm we recommend is made in Ireland, with hand-soldered circuitry and noticeably more components. A typical mass-produced alarm has far fewer.
Why false alarms matter more once alarms are interconnected
Under the Queensland rules the alarms are interconnected, so when one goes off they all go off. An average home now needs about six alarms, so one false alarm sets off six at once.
The noise reaches the neighbours as well, and someone has to get there and stop it.
What we see in a humid summer
Humidity is when cheaper alarms tend to play up. With the alarm we recommend we get very few callbacks. With typical alarms, in the middle of a humid summer, we can get one to three false-alarm callbacks a week.
What to ask before alarms are fitted
Ask which alarm is being fitted, where it is made and how long its warranty runs. We recommend Brooks alarms, which carry a three to seven-year warranty depending on the model.