FIRE DETECTORS-6
CO FIRE DETECTORS
The FSIB introduces the sixth in a series, on types of detectors available for the many and varied applications one might face.
CO Fire detectors
CO or Carbon Monoxide detectors are used to detect carbon monoxide gas which is colourless, odourless and tasteless that is extremely harmful to humans and animals. Carbon monoxide (CO) is created as a by-product of incomplete combustion of fuels containing carbon.
Applications
CO detectors are used to sense flow burning, smouldering fires, ideal for use in sleeping accommodation such as:
- Hotel rooms
- Student accommodation
- Old age homes
CO detectors are immune to cigarette smoke and steam from showers.
How do they work?
Carbon Monoxide detectors contain a long-life electro-chemical carbon monoxide sensor which is tolerant of low levels of common vapours and household products. It has a shorter lifespan than optical or ionisation detectors.
Where should we NOT use it?
Whilst the CO detector is good for clean environments it should not be used around areas where gas may be present. It is not suited for corridors, kitchens or parking garages.
Where can it be installed?
CO detectors monitor invisible gas that will move around a room and can be installed at any level; however, to comply with fire standards it should be mounted on the ceiling or roof of the protected room.
If it is to be installed into a bedroom it can be mounted on the wall above the door leading to the corridor or adjacent room.
Installation Guidelines
When installing CO detectors, consider the following general guidelines:
Spacing:
CO detectors should be spaced as per smoke detectors and at the same height limitations.
SANS 10139 specifies maximum coverage of 5m from any wall and 10m apart.
Advantages of CO detectors
CO detectors are not susceptible to steam, or cigarette smoke often produced in accommodation units. They have proven to sense smouldering fire conditions quicker than optical detectors due to sensing the gas being produced before actual smoke can be seen, making them ideal for bedroom areas.
Advantages include:
- Enhanced detection capability
- Ideal for smouldering fires
- Less susceptible to false alarms caused by steam than smoke detectors
False alarms and maintenance
CO detectors may false alarm if they are installed near to kitchens or areas where gas may be present, or produced due to production processes.
Choosing the correct application for these devices is important along with regular inspection, testing, and cleaning that can help maintain their reliability.
Conclusion
CO detectors are an important part of the fire detection designer’s armoury and should be considered for use in bedroom areas particularly.