The LWF Blog
Fire Safety Engineering for Design – Fire Detection & Alarm Systems – Part 164
January 3, 2024 11:46 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 163, LWF began to discuss audible and visual alarms. In part 164, we continue to look at the recommendations and guidance for fire alarm sounders as per BS 5839-1.
While an alarm system for general use should have a sounder level of 65 dBA (or 5 dBA above background noise), an alarm system which is to be used in premises where people sleep, such as hotels and boarding houses, should have a sound level of at least 75 dBA at the head of the bed. For this sound level to be achieved in each room, it may be necessary to install an alarm sounder in each bedroom.
In some very loud environments, such as nightclubs, the background sound can be so high that an alarm sounder would have very little effect. In these cases, it is necessary to disconnect the music upon activation of the fire alarm. Systems can be designed to do this automatically.
Where one or more of the occupants of a building may be deaf or have hearing issues, there are various ways of ensuring everybody is aware of the fire alarm sounding. The simplest and often the most effective is for other people in the premises to let them know. This responsibility should be allocated to specific persons who will be working in the same area at the same time. The system between the warner and the person with hearing disabilities should be tested during fire drills. Another option for when a person with limited hearing is working alone is that radio paging may be used.
In addition, systems can be put into place alongside the fire alarm system to activate flashing beacons as a warning and in the case of sleeping environments, specially-designed vibrating discs for use under a pillow or mattress, the intensity of which causes the sleeping person to wake in time to evacuate.
The UK’s Equality Act 2010 and Approved Document M – Access to and use of buildings should both be consulted with regards to making provision for people with disabilities in a fire situation.
In part 165 of LWF’s series on fire engineering, we will continue to discuss the recommendations and guidance for fire alarm sounders. 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.