
Smoke Detectors
Smoke detectors have been in use for many years, in both private and public institutions and have been responsible for the saving of numerous lives, by sounding an alarm when levels off smoke in a room are elevated.
How does a smoke detector work?
There are basically two kinds of smoke detectors,
- Photoelectric, which is triggered when the smoke particles block the light on a sensor in the device, and
- Ionization, which operates with a small electrical current which triggers the alarm when it is blocked by the smoke.
In some instances the smoke detector may also include a heat sensor.
Which smoke detector should you use?
Ionization smoke detectors have a better response to smoke from flaming fires than photoelectric alarms. On the other hand, photoelectric smoke detectors have a faster response to smoke from smouldering fires. If possible, install both types through your home. But if this is not an option, install at least one type of smoke detector.
Where is the best place for a smoke detector?
Where you place your smoke detector is important as it needs to detect smoke
in a room and warn of a possible fire, however when one builds a fire in an
indoor fireplace it is inevitable that some smoke will filter into the room
so too close to the fire is not ideal, as the alarm will be triggered in vain.
The ceiling is generally considered a good place, as smoke rises and starts
to accumulate below the ceiling. However, windows and doors leading to the outside
are not recommend as smoke might not be detected.
Rooms with fireplaces and kitchens are top priority when installing a smoke
detector, followed by bedrooms. If you do not have a smoke detector in each
bedroom, be sure to place one in an area central to the sleeping quarters, also
ensure that the alarm sounds loudly enough to wake the occupants of the room.
It is always prudent and preferred that you seek professional advice and have
your smoke detector supplied and installed by a technician.
Maintaining smoke detectors
- Your detector should have a button for testing purposes, push this at least every 3 months. Note that this is just to test the alarm sound, and not testing for actual smoke detection.
- Change the batteries every 6 months.
- Keep the detector free of accumulating dust
- Your detector will have been issued with a manual read it and follow any other maintenance instructions.
Some smoke detectors are more sensitive than others and if you have an indoor fireplace the unavoidable bit of smoke may enter the room and trigger the alarm. Do not disarm the smoke detector, or remove the batteries as it is so easy to forget that you have done so and it won't work at a time when you might need it most.
What is the difference between a Smoke Detector and a Carbon Monoxide detector?
Carbon monoxide monitors are just that, they are designed to detect and respond to high levels of CO in a room, while a smoke detector sounds the alarm when smoke is detected.
Why can Smoke Detectors go off when there is no smoke?
Any of these reasons can cause a smoke detector to go off without the presence of smoke:
- The cover or sensor chamber is dusty or dirty
- The cover or sensor chamber is covered or clogged with insects
- Power interruptions
- A loose connection
- Humidity, such as near a bathroom