The LWF Blog
Facilities Management – Fire Detection and Fire Alarm Systems – Part 8July 29, 2016 9:13 am
In our recent blog series for those who work in Facilities Management, we have been looking at fire detection and fire alarm systems. In Part 7, last week, the different types of detector were discussed and leading on from that, this week we’re going to talk about Aspirating Smoke Detection Systems, which can be useful in certain high-risk or high-value areas.
While life preserving fire alarm systems will look to alert occupants to the presence of fire in a building so they may evacuate, and property based fire alarm systems will alert the fire service as a priority to avoid damage to the building or contents, an aspirating smoke detection system is used to protect a specific area of high value, most often a server room or complex electronic equipment.
The system works by drawing in air samples via a pump or fan to a smoke detector. This smoke detector is most likely to be an optical type, rather than an ionization chamber detector. Because it is dealing specifically with the small samples of air collected, it is much more sensitive than a conventional room smoke detector, in fact, it can be as much as several hundred times more sensitive.
This greatly increased sensitivity means that the system can detect even a very small incident, such as the burnout of an individual component within a machine. Such a small burnout would not register on a traditional fire alarm system and in this case, the very tiny amounts of particulate matter can be detected. It is often the case that aspirating smoke detection systems can be incorporated within an air conditioning unit, so that it samples the air as it is returned to the system.
However, their use is not limited to a small area which requires protection. They are also used sometimes in multi-storey buildings with an atrium, so that the system can sample the air carried by pipes for smoke from the different levels of the premises.
They are also found in protected buildings such as stately homes. In this case, it is most often not the extreme sensitivity of such a system which is the attraction, but that it can operate whilst being practically invisible. The pipes for the system can be installed above ceilings and below floors with only a very small drill through for a capillary tube.
Aspirating Smoke Detector systems are also useful for those areas of a building which are not easily accessible – for instance in those areas such as atriums where a very high ceiling height can preclude regular maintenance visits. Although a certain amount of maintenance is still required, it needs less than a point smoke detector system, for instance.
In next week’s blog, we’ll look at Flame Detectors and Combustion Gas Detectors and examine what they might be able to accomplish. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact Peter Gyere in the first instance on 0208 668 8663.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.