Before installing emergency lights, it is important to develop a plan for the most effective use and placement of those lights. Emergency lighting units can be expensive and as a facility manager, you are responsible not only for obeying all governmental regulations, but doing so in the most cost-effective way possible.
According to the various emergency lighting regulations that deal with placement, you are required to install emergency lights in all areas where personnel are likely to be found, and all egress routes from the facility, up to public ways (sidewalks and streets) or safe assembly areas. This essentially means that the following areas need to be lighted:
Safety regulations require that the entire egress route be lighted to a minimum level of 1 candlepower measured at a height of 1 foot above the floor. When locating your safety lights, it is important to keep this consideration in mind at all times. Distance between light units depends upon the amount of light (measured in lumens) provided by that particular lighting unit. As the actual amount of light produced depends upon the voltage, wattage and efficiency of the bulb, we cannot give you an accurate distance between light fixtures here.
All areas where personnel or visitors to the facility are likely to be found must be illuminated for egress in the case of emergency or power loss. This means that corridors to all exits must also be illuminated along with the exit doors themselves. Additionally, exterior walkways leading from those egress points to a public way (sidewalk, street) or safe assembly area must be lighted.
Since every area where people are likely to be present requires emergency lighting, this can lead to a large number of emergency light fixtures. While individual offices that are occupied by only one person may not be required to have emergency lights, they do need to have the corridor outside of the office adequately lit.
In a large room, such as a warehouse or industrial facility, perimeter lighting of the room may not be enough. In these cases, lights will have to be interspersed throughout the room, either attached to columns or to the ceiling. In the case of warehouses, which typically have high ceilings, it is more practical to attach the emergency lighting to the storage racks in the warehouse, about 10 feet above floor level. This prevents the light from dissipating before it reaches ground level, where the light is needed. Caution must be taken in the location of these rack mounted lights to insure that they will not become damaged in normal operations.
In corridors, emergency lights should be spaced close enough to insure that the light from one unit slightly overlaps the next unit; preventing there from being an area where the lighting level drops below the minimum requirement.