Safety, orientation and visual interest are high priorities in circulation environments. Colour rendering should be perceived as natural, since appropriate facial recognition contributes to the sense of security and potential worker interactions. Vertical illuminance on walls enhances the impression of brightness in the environment.
If a corridor is a means of emergency egress, minimum criteria illumination and uniformity will be established by code. Above that, horizontal illuminance and uniformity are only priorities where there are changes in level or materials, such as stairs, ramps or thresholds. Each of the following modules show alternative energy effective lighting designs for enclosed office corridors. These are only a sampling of valid approaches, but each adheres to the following goals for windowless circulation spaces:
The control strategy listed below can be used in combination with the other strategies to achieve the greatest energy savings. Occupancy times and patterns should be understood before finalizing control system design. In egress corridors, it may be possible to meet code required illumination with every other or every third luminaire, but uniformity may not be acceptable. Consider multi-level ballasts that reduce the light levels in all fixtures for greater uniformity.
Controls should be designed to meet requirements for local codes related to egress. Where occupancy rarely occurs after normal business hours, timeclocks may be used to reduce lights to meet minimums for egress, safety or security. Where some intermittent activity is likely after hours (overtime workers, cleaning crews, security personnel), timeclocks may keep lights on during peak occupancy hours, but pass control to occupancy sensors (automatic on) toward the end of the workday and for the remainder of the night,
Consider multi-level ballasts that reduce the light levels in all fixtures for greater uniformity. Zones for occupancy sensor in corridors should be reasonably large so that the occupants are able to see far enough ahead (35-50 linear feet) to feel secure. The sensors should be set to auto-on to allow the lights to automatically turn on or increase as soon as a person enters the corridor from any point.
Decorative lighting, and wallwashing that does not contribute to security or safety can be switched off after normal hours of occupancy.
Demand reduction can be accommodated, but is less needed after peak afternoon hours. Reduction must not go below minimum light levels required for safety or code compliance for paths of egress.