Planning & Specifying
Proximity, Shape and Size of ExitsThe configuration of walls adjoining the exit way, the amount of space devoted to exit passages and travel distance to exits should be considered when determining the number and placement of emergency lighting units. For example, it is important to place emergency lighting at an intersection of a corridor or hallway. If it is a large area, additional units may be needed to provide adequate light to see any objects blocking the exit path.
Codes and regulations establish guidelines for emergency lighting equipment; however, there may be circumstances that call for more than minimum standards. Incorporating the right combination of elements into emergency lighting design provides a higher degree of safety and allows people to exit a building quickly and safely in the event of an emergency. The best emergency lighting system is carefully planned for a specific building and its occupants. As a part of this planning process, it is important to consider a variety of factors. We have listed some of those below.
Intended Use of a Building
Additional emergency lighting may be required depending on the types of people using a facility. Elementary school children, older people and individuals with special needs require more emergency lighting than apartment residents, college students or office workers. Retail situations where valuable merchandise is accessible or high-security facilities may also require extra illumination. Adequate lighting can be especially critical in hospital settings (e.g., operating and emergency rooms).
Ceiling, Floor & Wall CharacteristicsEmergency lighting levels are affected by the color and texture of surrounding areas. Light-colored ceilings, walls and floors with smooth surfaces require less emergency lighting because of their reflective characteristics than do darker ceilings, floors and walls with rough surfaces.
Occupancy & Building KnowledgeThe number of people expected to occupy a building and their knowledge of its interior also influence the level of emergency illumination needed. Large numbers of people unfamiliar with exit paths require more emergency lighting than smaller numbers of people who know the surroundings. Consequently, auditoriums, convention halls and sports arenas often need higher levels of emergency illumination than office buildings and warehouses.
Placement of Emergency BallastsStrategically placed fluorescent emergency ballasts help occupants avoid potential obstructions near the path of egress. Although exit signs with directional indicators are required and are important to occupant safety, fluorescent emergency ballasts in corridors, intersections and stairwells assist occupants in clearly identifying the exit route. To ensure that emergency lighting is continuous throughout the path of egress, use fluorescent emergency ballasts in addition to other emergency lighting unit equipment. Providing evenly spaced emergency lighting enhances safe, quick movement to exits and prevents excessively bright-to-dark spots along the path of egress. Depending on the facility, it may be better to specify a greater number of emergency ballasts with lower light levels than to specify a lesser number of widely spaced emergency fixtures with higher lumen output.