The LWF Blog

Fire Safety for Facilities Management Personnel – Voice Alarm Systems – Part 212

July 31, 2023 10:54 am

Lawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 211, LWF talked about the second reason there has been an increase in the use of voice alarm systems in recent years. In part 212, we look at the design code of practice for voice alarm systems.

Since the early 1970s, fire alarm design codes have included reference to what we would now call voice alarm systems. In the early decades of use, the reference contained was usually to public address systems being used in lieu of conventional fire alarm sounders. The main reason for inclusion was to ensure that the sound systems could satisfy the same principles adopted for fire alarm systems.

However, the guidance given was quite limited and, as a result, installations were sometimes inadequate for the purpose and this led to issues and contention.

Systems installed in numerous complex builds, such as shopping centres, failed to meet the most basic principles of fire alarm system design. The idea of having a voice alarm system was attractive, whereas the care needed to ensure it was suitable for purpose simply wasn’t taken when considering the engineering design of the systems.

In 1998, a dedicated code of practice for voice alarm systems was introduced. BS 5839-8 is a code of practice for the design, installation, commissioning and maintenance of voice alarm systems and has been subject to updating since its introduction. The standard considers all elements for which there is an analogous requirement for fire alarm systems, along with aspects of the audio system design that are particular to voice alarm systems.

Particular guidance on voice alarm systems for sports stadiums is available in BS 7827 ‘Designing, specifying, maintaining and operating emergency sound systems for sports grounds, large public buildings and venues – code of practice’.

There is also a code of practice on the subject of sound systems for emergency purposes, originally issued as BS EN 60849, but now replaced by BS EN 50849. The standard applies to sound reinforcement and distribution systems used to effect rapid and orderly mobilisation of occupants in an indoor or outdoor area in an emergency. It does not apply to emergency sound systems used for evacuation in case of fire emergency, whether it is connected to the fire detection and fire alarm system or not.

In part 213 of this series, LWF will look at the factors to consider in the design of a voice alarm system. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.

 

Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 35 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.

 

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.