The LWF Blog

Fire Safety Engineering for Design – Fire Detection & Alarm Systems – Part 135

June 5, 2023 10:29 am

LWF’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 134, LWF talked about the different types of fire alarm system. In part 135, we consider how it is best to manage false alarms.

The effective and safe management of fire safety in a building can be severely undermined by frequent false alarms from the fire alarm system. When a fire alarm frequently gives false alarm signals, the result can be that the alarm signal is ignored by the building occupants, or the system is deactivated to avoid disruption.

Business continuity and effectiveness may also be affected. The need for evacuation, whether full or partial, can be crippling to a business. Large performance or sports venues, airport terminals etc. are very adversely impacted by the need to evacuate occupants, as are manufacturing businesses with production lines that must be shut down.

The impact of repeated false alarms is significant and the issue must be addressed with every effort being made to reduce the frequency.

One of the most common causes of false alarms is that an incorrect specification of detector head has been used for an environment. For example, smoke detectors should not be used in kitchen areas, as burning food (toast is a major contributor) is likely to set off the smoke detector.

Beam detectors used in areas where forklifts may interrupt the ‘line of sight’ may also result in false alarms.

Not all false alarms are due to the accidental triggering of the detector heads of the fire alarm system. The misplacement of manual call points can result in the ‘break glass’ points being deliberately or accidentally activated. The solution in this instance is to re-site the manual call point to somewhere more appropriate, or to provide a cover if it is accidentally knocked. In some buildings, it is appropriate to omit some manual call points from the fire alarm system.

While small changes to the fire alarm system can resolve many situations in which there are repeated false alarms, there are other situations where the system itself can be set up to filter potential false alarm signals.

In part 136 of LWF’s series on fire engineering, we will continue to discuss false fire alarms and what can be done to remedy repeated false alarm signals. 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.