How to choose between brands
There is no general-purpose smoke alarm for all locations. The correct choice is important to avoid false alarms, as excessive false alarms can lead to the householder disabling the smoke alarm.
There are two choices of smoke alarms:
240 Volt Smoke Alarms (Also called hard-wired smoke alarms)
A 240 volt smoke alarm is connected to a home’s electrical system and has battery back-up power supply.
Advantages
- Considered more reliable in the longer term
- Early warning - occupants alerted in the shortest possible time
- Uses a battery to provide back-up power if the AC power fails
- Models can be interconnected which sound alarms in all connected units
- Can come with a long life Lithium Battery - built-in and tamper proof
- Power-on indicator
- In some models a hush button - to stop nuisance alarms
- Test button - to ensure correct operation
- Tested by Scientific Services Laboratories to comply with AS3786
- Some can be purchased with a rechargeable battery (non-replaceable)
Disadvantages
- More expensive
- Need to be installed by a qualified electrician
9 Volt Smoke Alarms (Also called battery operated smoke alarms)
A 9 volt smoke alarm is stand alone and operated only by a battery.
Advantages
- Easy to install
- Test button - to ensure correct operation
- Low battery indication
- In some models a hush button - to stop nuisance alarms
- Battery missing indicator
- Tested by Scientific Services Laboratories to comply with AS3786
- Some models can be interconnected
Disadvantages
- Battery needs to be replaced regularly
Smoke alarms can be installed either stand alone or interconnected. Interconnection allows all smoke alarms to sound simultaneously should any one alarm activate. All occupants are alerted, maximising the opportunity for escape. Children’s bedrooms should have a smoke alarm, and be connected to the parent’s bedroom because children sleep much sounder than adults. A significant percentage of residences fitted with smoke alarms remain unprotected due to depleted or missing batteries.
The installation of smoke alarms in new residential properties became compulsory in Queensland in 1997. The ‘Standard Building Regulation 1993’ outlines that in Queensland, hardwired smoke alarms are required to be installed in all new properties and those properties that are being significantly renovated (i.e. renovations exceeding more than 50 percent of the original building, measured over the roof and the external walls).
(Building Code of Australia, 1996 Vol.2 3.7.2).
Generally, there are two kinds of smoke alarms – ionisation and photoelectric.
Ionisation Smoke Alarms
They ‘smell’ the smoke. This type detects invisible particles of combustion e.g. from cooking toast. They activate more quickly for fast, flaming fires and little visible smoke.
Advantages
Cheaper than other types
- Very good with fast flaming fires with little visible smoke
- Suitable for general use
- Less prone to false alarms due to dust and steam
Disadvantages
- Very susceptible to nuisance alarms due to cooking
- May be slow to respond to slow smouldering fires
- Contain radioactive material
Photoelectric Smoke Alarms (also known as optical)
These ‘see’ the smoke (optical). This type detects visible particles of combustion e.g. smouldering cigarette smoke. They respond to a wide range of fires, but they are particularly responsive to smouldering fires and the dense smoke given off by foam filled furnishings or overheated PVC wiring.
Advantages
- Good for smouldering fire and dense smoke
- Not as prone to cooking nuisance alarms
- Contain no radioactive material
- Suitable for general use
Disadvantages
- Prone to nuisance alarms from dust and insects - must be kept clean
- More expensive
Your protection against fire increases with the quality and type of smoke alarm that is installed. Research indicates that photoelectric smoke alarms are generally more effective than ionisation types across a wider range of fires experienced in homes. For this reason, QFRS recommends that photoelectric smoke alarms be installed, especially if you are installing only one alarm. If you already have smoke alarms installed, QFRS recommends that you supplement the existing alarms with photoelectric types, especially between sleeping areas and exits from your home (e.g. hallways); and at the end of the service life of existing smoke alarms, replace them with photoelectric types.
It is expected that stocks of photoelectric alarms will become more readily available at retailers as demand increases.
Other Smoke Alarm Options
These include:
- Alarms for the hearing-impaired
- Alarms with emergency lights
- Special models for kitchens and caravans
- Inter-connectable models that sound alarms in all connected units
What to look for?
Queensland Fire & Rescue Service recommends you buy an alarm which carries the Standards Australia Mark or is Scientific Services Laboratory (SSL) labelled. According to legislation smoke alarms installed must comply with AS 3786-1993. Despite this requirements, some smoke alarms that do not meet the Standard are still available in some stores. The Office of Fair Trading have confirmed that the sale of these is not against the law.
QFRS strongly recommends, when purchasing smoke alarms, people check that the smoke alarm they are buying complies with the Standard. The following labels will appear when smoke alarms complying with AS 3786-1993 are purchased.
For further information go to CSIRO's Activfire website which provides consumers and fire safety advisers with details of smoke alarms that have been verified as conforming with requirements of Australian Standard AS 3786-1993 http://www.activfire.gov.au/smokeAlarms.asp
Last updated 5 June 2006
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