EN54-23: Shedding light on the new standard for visual alarm devices
After an extension by the European Commission to the coexistence period on the 31st December 2013, a new mandatory European product standard [EN54-23: Fire alarm devices – Visual alarm devices] will be introduced. Paul Pope of Apollo Fire Detectors considers the implications of this new European product standard and the reasons behind its introduction.
The aim of EN54-23 is to enable manufacturers to design, produce and have certified Visual Alarm Devices to a specified visual coverage and mounting position to ensure that any individual with a hearing impairment is notified in the event of a fire. This includes individuals that are classed as deaf or hard of hearing, and also individuals whose hearing may be temporarily affected by external factors such as areas of high ambient background noise, the use of ear defenders, or even the intentional limiting of an audible alarm. In these situations, audible alarms – sounders – are not considered to be effective as the only primary means of warning device.
Following the introduction of the UK Equality Act and Part M, one solution which has become popular, is a combination of audible and Visual Alarm Devices (VADs) – historically known as beacons. VADs are particularly useful in areas such as hotels, hospitals, care homes, and shopping centres to name a few. Following a site/risk assessment VADs should be positioned wherever hearing impaired individuals may be unaccompanied e.g. bathrooms, toilets and bedrooms. They are not, however, intended to waken people from sleep and in these situations should be used in conjunction with Tactile Alarms.
Until recently, no European product standard existed to determine the light output performance criteria and installation requirements of VADs. This resulted in inconsistency across how manufacturers declared their products’ performance. This is all set to change with the introduction of EN54-23, manufacturers will have to meet specific requirements, test methods and performance criteria for VADs. It is hoped that this will enable those responsible for specifying a fire detection and alarm system to compare like with like and identify the most suitable VAD for each application.
EN54-23 will address light distribution patterns or specifically, a product’s coverage volume performance. VADs will be classified into three categories depending on the application in which they will be used: ceiling mounted, wall mounted and open class devices. The size of each product’s coverage volume will be determined by the distance at which the illumination of a surface perpendicular to the light source achieves illumination of 0.4lux (0.4lm/m2).
For the wall and ceiling mounted categories, the VAD has to achieve a specific dispersion pattern, whereas the guidance for open class devices is intended to allow some existing designs to be used or cater for specialised applications. The specifics for each category are:
- Wall mounted: mounting height is limited to a minimum of 2.4m and illumination is set to 0.4lux over a cubical space
- Ceiling mounted: mounting heights are fixed at 3m, 6m and 9m (using VADs at heights above 9m becomes inefficient) and ceiling devices are required to illuminate cylindrical space
- Open class: the manufacturer is permitted to set the coverage shape as there may be an advantage to using the product in specialised applications
Manufacturers will have to appoint an EU Notified Body to test and certificate a VAD’s coverage volume. When tested, each VAD will be given a coverage volume specification code. Manufacturers will have to make this available on the product itself or on supporting documentation. Apollo, for example, will declare this code in our product guides.
Other EN54-23 requirements that manufacturers must ensure their VADs comply with relate to luminous intensity (min 1cd/for 70% of all measurements points and max 500cd for any measurements point to prevent glare), a flash rate of between 0.5Hz and 2Hz (to avoid the risk of photosensitive epileptic seizures), and the use of only white or red flashes. Importantly, the chosen colour must be consistent across the whole site, which is particularly important when extending an existing system.
Where an assessment has been conducted and the need for EN54-23 VADs within escape corridors or staircases has been identified, there is little guidance in the codes that helps to mitigate the risk of glare to the occupants during evacuations using the new high output VADs.
The LPS1652 Code of Practice for Visual Alarm Devices used for Fire Warning codes places a high emphasis on the designer to account for the highest background level lighting. This may result in excessive glare to the occupants during an alarm condition in periods of low light. If glare occurs, it is possible that susceptible individuals will suffer from visual impairment. This must be considered as part the of evacuation strategy for those at risk.
While the new EN54-23 standard and associated codes are a welcome move, Apollo believes it is important to remember that after 31st December 2013 existing non certified EN54-23 products could potentially still be used on fire systems in and outside of the European Union. They cannot be used as visual alarms to give a primary fire warning in Europe, but they could be used as supplementary visual indicators as part of an agreed specification between all interested parties. There is certainly still going to be a market for visual indicators moving forward and we would hope that the industry applies the use of VADs appropriately to suit the risks and improve life safety protection long into the future.
We would encourage those responsible for specifying fire detection and alarm systems to review the changes to the standards and codes, consult with the relevant interested parties very early on during the consultation and design stage, refer to the risk assessment and evacuation strategy for guidance on where VADs are actually needed and make a sensible decision based on each individual application.
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The FIA and LPCB have jointly produced a useful guide on the standard entitled ‘CoP 0001: Code of Practice for visual alarm devices used for fire warning’, which can be downloaded at http://www.redbooklive.com/pdf/CoP-0001.pdf
For further information, please visit www.apollo-fire.co.uk