The LWF Blog
Fire Safety for Facilities Management Personnel – Emergency Escape Lighting – Part 166September 5, 2022 11:30 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 165, LWF discussed emergency escape lighting. In part 166, we look at design choices for emergency escape lighting installations.
There are three main types of emergency escape lighting installation to consider when making design choices. They are self-contained luminaires, central battery systems and emergency generators.
Self-contained luminaires are the most commonly found form of emergency escape lighting installed in premises. They are often the most practical for smaller premises and also for retro-fitting into existing buildings.
The luminaires are able to work independently of mains electricity and each other. Each fitting comprises a battery, charger, changeover device, inverter (where lights are fluorescent) and lamps within its housing. It is possible for the control gear for the light to be housed outside the light housing but it should be sited within 1 metre.
It is possible to convert existing mains luminaires into self-contained units by adding a conversion pack. This commonly operates a small lamp within the main luminaire but in some, more sophisticated units, power is provided to the existing lamp.
The self-contained luminaire works by being connected to the existing lighting circuit and during normal conditions, the battery is charged by the lighting circuit. Upon failure of the normal lighting circuit, the cessation is detected by the luminaire and illumination is automatically provided.
BS EN 1838 provides guidance on what is required in terms of conformity of luminaires in the UK and Europe.
The provision of emergency escape lighting is at its easiest and most economical when using self-contained luminaires. They are quick to install and can be adaptable to suit changes to layout of a building.
It is commonly touted that the batteries in self-contained luminaires are maintenance-free and this is true to a point. The battery life is finite and therefore they must be checked regularly and replaced as they may fail 4-5 years after installation (or sooner if they are faulty or situated in arduous environments).
The danger with such systems is that they are installed and then forgotten about, which can lead to them not operating when the situation requires it. It is necessary to regularly test the entire system of luminaires and this may be a lengthy process when each has to be tested individually.
The cost of replacing batteries can be surprisingly high and eat into the initial cost savings made when the system was first installed, when compared to other, more expensive, systems.
In part 167 of this series, LWF will continue to look at the types of emergency escape lighting system, by considering Central Battery Systems. 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 25 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.