How often do Smoke Alarms need to be tested?
As per Australian Standards AS3786
Smoke and Thermal detector alarms need to be tested yearly (every 12 months) when the fire doors are being tested to minimize disruption to anyone on the premises. Every house, home, unit is required to have a sufficient number of smoke alarms installed from 1 May, 2006. It is of the upmost importance that smoke alarms be located on every level of your home. Smoke alarm batteries must be replaced every 12 months at least. We can test and if needed replace any type of smoke alarm you may have.
What are the types of Smoke Alarms?
There are three types of smoke detectors on the market
· Dual sensor alarms which use both ionization and photoelectric technology.
Ionization smoke alarms
Ionization smoke alarms are best at detecting the small particles typical of the smoke from fast, flaming fires as opposed to smoldering fires, which produce smoke with larger particles. Ionization smoke alarms hold a small amount of radioactive material (Americium-241) between two electrically charged plates, which ionizes the air and creates a current between the plates. When smoke enters the chamber, it disrupts the current and activates the alarm.
Ionization smoke alarms can be triggered by the smoke produced by burnt food or by steam from a shower, so you may get more false alarms if the alarm is placed in the kitchen or near a bathroom.
Photoelectric smoke alarms
In a photoelectric smoke alarm, a light source is aimed into a sensing chamber at an angle away from the sensor. When smoke enters the chamber, the light defracts and reflects onto the light sensor, which triggers the alarm. These types of smoke detectors are best at sensing smoldering fires that create a lot of smoke without many visible flames. While not as prone to false alarms as ionization smoke detectors, photoelectric alarms can randomly be set off by a buildup of dust in the unit.
Dual sensor smoke alarms
Dual sensor smoke alarms combine ionization and photoelectric sensors into one unit. Some models require both sensors to be triggered before the alarm will go off, but this may delay the alert from sounding. Other models only require one of the sensors to be tripped, but that also creates the potential for more false alarms.
Things to consider before buying
In addition to the type of smoke detector, there are several other safety features that should be taken into consideration.
Alarms can either be powered by a battery or hardwired into your home’s electrical system with backup batteries in case the power goes out. Hardwired alarms are the recommended option and are sometimes required by the BCA (Building code of Australia). Though they generally require professional installation, the safety advantage is that they can be interconnected with the other smoke alarms in your home.
Battery only alarms are easy to install and they’ll continue to work during a power outage, but the batteries will need to be replaced once or twice a year. Some models use lithium batteries, which may last for up to the life of the alarm which is 10 Years. Some alarms can be plugged into an outlet, but the ideal placement of an alarm is on or near the ceiling.
As mentioned above, you can link some smoke alarms to all the units in the house so all of them will go off if one is triggered. This is an important feature for homes with multiple levels where you may not be able to hear an alarm in a far corner of the house. Many newer homes have this wiring already in place, or you can purchase alarms that will connect wirelessly.
Being able to silence an alarm with a button is much better than disabling the unit—since then you decrease your chances of forgetting to put the batteries back in the unit. The silence button is a temporary measure and the alarm will sound again if whatever triggered it persists.
Some smoke alarms have one silencing button while others have two—one for a false alarm and one for a low-battery warning. The low-battery warning can be silenced for longer stretches of time than the regular alarm, but it varies from model to model.
A flashing light as part of a smoke alarm’s warning system is an important feature for anyone who is hearing-impaired. Some alarms also come with a safety light that provides illumination in the dark.