The LWF Blog
Fire Safety Engineering for Design – Fire Detection & Alarm Systems – Part 155
October 23, 2023 10:48 amLWF’s Fire Safety Engineering blog series is written for Architects, building designers and others in the construction industry to highlight and promote discussion on all topics around fire engineering. In part 154, LWF talked about aspirating systems. In part 155, we continue to discuss aspirating systems and what environments they may be suitable for.
One of the significant benefits of aspirating systems over other types of fire detection system is that the pipework can be hidden in the ceiling or behind walls, so there are no parts of the system visible in the rooms the system protects. Heritage and listed buildings can benefit from this type of installation.
They are not adversely affected by high air flow. Aspirating systems draw the air towards the pipework and so they can be used in areas where smoke detection might otherwise prove difficult, such as atriums, stadiums, gymnasiums and very large rooms with high ceilings. Dust is not an issue either, meaning they are suitable for installation in car parks and other similar environments.
Care should be taken when installing an aspirating system in unusually high spaces. It is often the case that the smoke layer caused by a fire will form below ceiling height (stratification). Where this is the case, the pipework for the aspirating fire detection system must be installed below this height.
The cost of purchasing and installing an aspirating system will be a little more than a conventional fire detection system but the reduction in maintenance costs will be marked and should be taken into consideration.
The control panel for the aspirating fire detection system can be configured to respond in one of three ways, depending on the level of smoke that is detected:
Level 1 – Notify the responsible personnel that smoke has been detected
Level 2 – Switch off air vents and/or switch off power supplies to certain areas to prevent the fire from igniting
Level 3 – Give a general fire alarm condition and signal other systems and communication centres
The fact that the actions given for Level 2 are possible following detection is down to the very early stage at which these systems can detect fire, even before the visual signs of fire are present.
BS 5839-1 gives recommendations for the design and installation of aspirating fire detection systems, also known as Air Sampling Detection (ASD) systems.
In part 156 of LWF’s series on fire engineering, we will look at flame detectors and gas combustion detectors. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.
Lawrence Webster Forrest has been working with their clients since 1986 to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact the LWF office on 0800 410 1130.
While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.