When considering the emergency processes and procedures within your building it is wise to make some appreciations of what you will need to do if the lights go out.
Whilst there are minimum requirements within BS 5266, these are the base line for your review and the overall planning should take some account of the following:
- Working Hours 8/12/24
- Disability and Special Needs provision including Refuge areas and WC’s
- Key risk areas WC areas, 1st aid post etc:
- Task lighting
- External areas – RV point – Parking
- Control systems – Fire alarm – Distribution boards – Lifts etc.
- Storage of flammable or combustible materials
- Potentially blocked escape routes
- Shared escape routes
- Welfare areas
- Kitchen cooking areas
When considering the needs of the site you must ensure that both the system design and the fittings used can deliver the relevant lux levels in the event of a loss of localised mains, relying on 0.5 or 1 lux in all areas will neither suffice nor comply, it may be necessary to get your incumbent partner to undertake a lux test to see exactly what you need both in the type of fitting and their location.
Emergency Lighting systems design notes expectations:
- Verify escape routes
- Establish fire alarm call point locations
- Establish position of fire safety signage
- Investigate possible hazards on escape routes
- Establish open areas that require emergency lighting
- Establish requirements for external emergency escape lighting
- Locate Lifts
- Locate moving stairways and walkways
- Establish locations for portable fire- fighting equipment (extinguishers)
- Locate WC, lobby, and closest accommodation over 8m2 gross area (or below 8m2 without borrowed light) for those with “special needs”.
- Locate plant, motor rooms and generators
- Locate and assess covered car parks
- Investigate the need for standby lighting
- Assess potential for CBU supply and routes of low risk for cabling
Design of Illumination
Having determined the positions and areas which need to be illuminated from the emergency lighting system the detailed design can commence as follows:
- Position the emergency luminaries onto a plan or drawing
- Verify the height of the units to give optimum performance
- Select the correct light for the environment
- Obtain detailed light distribution of light unit (lux level)
- Calculate the lux level
- Check uniformity
- Consider requirements for photoluminescent tape on walkways, gantries, and escape routes.
The relevance of the correct emergency lighting plan is even more important if considered within the environment where there might not be a fire alarm, maybe a residential high rise or in some commercial applications that have an M category system without detection.
The use of photoluminescence is not as widely used as it should be and is regularly overlooked.
It may be necessary to have photoluminescent tape around escape doors, arrowed floor direction and around machinery and areas to be avoided within evacuation.
Having the correct fitting giving the right lux levels is vital to ensure that in the event of a loss of mains supply the system works as intended, this is more relevant in areas of residential evacuation, in areas where the “route out” to a place of safety is complex and in environments where it is easy for visitors to become disoriented.
When in consultation with your incumbent contractor who should be BAFE/NICEIC certified the consideration for a lux test is recommended to ensure some appreciation of exactly what you need to safely evacuate your site, in particular sites that operate unsocial hours or where you have permanent residence issues for care homes, school dormitories etc where some may not be able to self-evacuate
As a guide for your site you should be looking at the following:
- 15 lux at the fire alarm panel
- 15 lux at stairway refuge points
- 5 lux at a call point
- 5 lux at a 1st aid point
- 5 lux at escape doors using panic bolts
In the event that your site has 60 minute escape lighting then an immediate full evacuation is required in the event of mains loss.
In the event of 3hr fittings these will require a full 24hr recharge facility so, to ensure some redundancy these need to be tested in a 50/50 split to ensure you have 50% of your available lighting should you suffer a mains loss within the recharge period.
In areas with low lux levels the importance of directional signage and photoluminescence is more pronounced as in some cases, if during a fire, smoke may create obscuration of the emergency fittings and having photoluminescent tape on the floor and stairwells will be essential.
In summary therefore the appreciation of where and how you use your emergency lighting, how it is supported by the directional signage and photoluminescence and your plans for evacuation need to form a major part of your fire strategy.