Adaptive Emergency Escape Lighting

The installation of Emergency lighting within a building is provided in the event of failure of the power supply to the normal lighting, with the lighting being powered from a source independent of that supplying the normal mains lighting, allowing the occupants to safely egress from the building to a place of safety.

This new Technical Specification was prepared by the CEN (Comité Européen de Normalisation) Technical Committee on Light and Lighting on behalf of all member states within the EU and EEA, and including the UK, entitled, ‘CEN/TS 17951:2024 – Lighting Applications – Adaptive Emergency Escape Lighting Systems’.

The objective of an emergency lighting system is installed to assist the building occupants to achieve a safe exit from the location in which they are situated, to a place of safety outside of the building, in the event of an emergency, through the use of both emergency lighting and emergency signage indicating the safe route to exit.

To assist in this scenario, adaptive emergency escape lighting can be used to revise the emergency escape routes, whilst also making the emergency signage more noticeable through the use of directional exit signs, which can be controlled to change their information depending upon the location of the fire or potential hazard, so as to direct the occupants away from an exit which may have become unusable due to that hazard.

This system, referred to as AEELS, can be installed to operate, either where at the time of the fire or other emergency, the directional signage would be adjusted and set based upon the criteria known at that time, that is at the start of the procedure for the occupants to leave the building, or alternatively a more sophisticated system can be installed to allow the directional signage can be changed during the evacuation process as more information on the building condition becomes available, thereby re-routing the occupants accordingly away from an exit which is no longer available as a means of exit from the building.

With all such systems in a building potentially in a fire condition, maintaining the signals between the AEELS control unit and each of the directional signs may present an issue if there is a failure across the system, thereby resulting in further directional information on routes to exit not being possible. In this event, the system would revert back to the original condition in accordance with EN 1838 design requirements, ensuring that the consistency across all directional signage is maintained, whilst also considering the risk assessment which would have been carried out previously.

This technical specification document specifies the lighting and the operational requirements for the adaptive emergency escape lighting system so that it can interact with the management and control systems, or alternately be given functionality to modify the operation of the emergency escape lighting according to situational requirements relating to the luminous flux output, escape directions and the characteristics and meaning of emergency escape lighting.

There are several terms and definitions contained within the technical specification document, starting with ‘adaptive emergency escape lighting’, which is the enhanced emergency escape lighting responding to various circumstances or according to predefined conditions.

The ‘adaptive emergency escape route signage’ is the emergency escape route signage which utilises internally illuminated escape route signs which can change the information that they display. An ‘adaptive emergency escape lighting system’, referred to as AEELS, is an electrically operated escape lighting system which provides directional guidance and adequate illuminance by means of a set of emergency lighting luminaires and directional indication that can manually or automatically change the escape route direction and improve the conspicuity or the emergency signage and optionally the lighting level of the escape routes.

The AEELS Control Unit (AEELS CU) is the hardware or software interface, either external or integrated in the luminaires with or without signs provided to control operation of an emergency lighting luminaire/system based on external sources/control interface, where the ‘AEELS Interface’ are the system components, software and hardware, necessary to provide input signals/commands to an AEELS control unit in an appropriate format.

For the purposes of this technical specification, Adaptive Emergency Escape Lighting Systems are regarded as a generic term of which there are several specific forms depending upon the configuration and available system inputs as shown below.

The directional signage shown below offers an example of a safety sign which can be installed and used to indicate to the building occupants that an escape route is no longer usable for evacuation during the fire situation or other emergency.

The sign would be as normal, indicating the route to exit, however when this sign no longer offered the occupants a safe route to exit, a red cross would appear, indicating that this route is no longer of use, however other sign formats can be used provided that they meet the requirements of this technical specification.