Designing an infrastructure has a wealth of building regulations that must be met, but there is always one paramount consideration – emergency lighting.
In the event of a fire or a power cut, the normal source of illumination fails and can lead to sudden darkness, thus causing potential danger to occupants with panic or physical accidents.
Emergency lighting is required to operate automatically and give enough light to enable all the occupants to leave the premises safely.
Guidelines for emergency lighting is provided by the British Standard for different levels of premises, including hotels, clubs, hospitals, offices and many more for complex installation
Types of Emergency Lighting
Emergency Escape Lighting – Provides illumination for those trying to leave the location. Important part of the Fire & Safety provision of a building and requirement of ‘Regulatory Reform (Fire Safety) Order 2005’.
Escape Route Lighting – Ensures all means of escape can be identified and safely used by occupants of the building.
Open Area Lighting – Allows sufficient illumination to guide occupants to reach part of building where escape route can be found.
High-Risk Task Area Lighting – Provides illumination for the safety of people involved in potentially dangerous situations. This lighting will ensure the proper shut-down process of procedures can be completed without risking the safety the operator and surrounding occupants.
What to Consider When Installing Emergency Lighting
The first stage of installing emergency escape lighting is the consultation and design process.
A designer, responsible person and fire risk assessor need to decide where emergency lighting is required and make up a plan showing the 5 key components – the type (power supply), mode of operation, facilities, duration and siting.
1.) Type (Power Supply)
The decision to use a central battery or self-contained system for emergency lighting is ultimately cost-determined. There are both advantages and disadvantages that need to be considered for your infrastructure –
- Self-Contained (Single Point)
Advantages – Installation is faster & cheaper, low maintenance costs, low hardware equipment costs and integrity of system greater as luminaires as it can be easily extended.
Disadvantages – Badly effected by environmental conditions such as high/low temperatures, battery life limited to 2-4 years and testing requires isolation on individual luminaire basis.
- Central Battery Source
Advantages – Maintenance is easier thanks to the one location, battery life can last from 5-25 years, environmentally stable in different temperatures and larger batteries are cheaper per unit.
Disadvantages – High capital equipment & installation costs, fire-resisting cable needed for each satellite luminaire, requirement of battery room to house cells & charger circuits and poor system integrity.
An installation with longevity and low maintenance as priorities will probably accept a central battery, whereas installation costs are a major consideration on smaller jobs, making the self-contained luminaire the most popular choice.
2.) Mode of Operation
A principal consideration that is mainly decided by the use of the premises – maintained or not maintained. There are several examples and combinations of the mode of operation for emergency lighting.
- Maintained emergency luminaire – Maintained and typically used in theatres, halls, cinemas, clubs etc to prevent total darkness.
- Non-maintained emergency luminaire – Emergency lights come on in failure of mains power supply, typically used in the workplace.
- Combined emergency luminaire – Luminaire energised with 2 or more lamps. 1 is energised by emergency supply and others are from normal maintenance/non-maintenance.
- Compound self-contained emergency luminaire – Maintained and non-maintained emergency lighting which includes an emergency power supply to a satellite luminaire.
- Satellite emergency luminaire – Maintained and non-maintained operation which receives its energy supply from an emergency luminaire.
Some emergency lighting can come with facilities which improve their testing and functionality for certain situations.
- Luminaire including test device – Contains self-testing modules.
- Luminaire including remote test device – System tested remotely by a centralised panel.
- Luminaire with inhibiting mode – Control mode used to inhibit the emergency lighting luminaire from working.
- High-risk luminaire – For risk task area lighting, the maintained luminaire should not be less than 10% of the required illumination to maintain task under normal regulations.
The time required to evacuate the premises depends on its size and complexity, which creates consideration for how long an emergency light should stay on for.
Duration is dependent on the evacuation time, but also on whether the normal supply returns automatically once restored after failing. The minimum duration of emergency escape lighting is 1 hour.
However, if the premises cannot be evacuated immediately, such as sleeping accommodation, the minimum duration of the emergency lighting is 3 hours.
5.) Siting of Luminaires and Emergency Signs
Once you have decided on a basic system outline, consideration needs to be given to the siting of your emergency lighting units and signs.
Luminaires and signs should show the emergency exit routes leading to the final exits, with close attention being paid to individual stairways, changes in floor level, corridor intersections, control rooms and outside of each final exit.
It’s not necessary to provide for all of the sections mentioned, but with a sufficient amount of emergency lighting, fire safety regulations and sufficient exits, your proposed scheme should meet the standard requirements.
Emergency Lighting is Important – Why not go LED?
When devising a plan for a premise, factors such as emergency lighting regulations should not be treated with any contempt.
A coherent strategy that allows exit routes to be easily identified and fire safety regulations to be followed will result in less panic and therefore less chance of danger in the event of the main power supply failing.