The LWF Blog

Fire Engineering Design and Risk Assessment – Radio Based Fire Alarm Control – Part 25.

November 17, 2016 1:04 pm

In our fire engineering design and risk assessment blog series for architects and building planners, we have been looking at types of fire alarm system and the standards which relate to them. Today we’re going to discuss radio based fire alarm systems, which should comply with BS 5839:1.


A radio based fire alarm system is one where the components communicate via radio signals. This means that there is no wiring between the detectors and the control panel, which means that installation of such a system may prove to be less costly and it can be installed and working much more quickly than a wired system.


Additionally, the amount of disruption to the building is minimal upon installation of a radio based fire alarm control, so the normal day-to-day operations can often continue while installation takes place.


If a site consists of more than one building within a certain area, a radio based system can often be a good choice, without wiring having to travel between the two. Such systems can be useful in buildings where damage to existing surfaces is not desirable or even not possible due to protected status, for instance.


Each detector is part of the system can be identified by the control panel, which makes for easy identification of the location of a fire, if it is triggered.

With a standard, wired, fire alarm system, the requirement for fire-resistant cabling can prove expensive so that it can continue to operate in fire conditions – at least for the amount of time the cabling is resistant. With a radio based system, the installation will typically operate for a pre-determined time.


Another huge benefit to a radio based fire alarm system is that the combination of reasonably easy installation and the lack of wires makes it ideal for protecting temporary events or installations in areas where there is not normally a fire alarm system.


Of course, there are disadvantages to such a system too. Each detector, device or call point within the system must have a local power source.


The receiver could potentially suffer from signals which interfere with its effectiveness. The allowed frequency spectrum of the radio waves is limited and this can lead to interference between simultaneous signals. For this reason, monitoring signals at regular intervals are not recommended, but this can mean that for some faults, there might be a significant delay in them being received by the control panel.


As with all buildings, events and potential solutions, each should be considered carefully and appropriate independent advice taken before installation.


In our next blog, we will look at power supplies for fire alarm systems. 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 for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 020 8668 8663.


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