More lighting has often been associated with safer environments but the generally accepted authority on lighting (IESNA) does not support this. Instead, the collective wisdom denotes a combination of good design elements that include appropriate lighting levels as well as other design features. This combination provides a complete package that supports safety and security elements such as visual identification capability and effective lighting for security cameras.
Energy savings opportunities exist for all major exterior elements including parking lots, streets and roadways, and other building mounted lighting. The universal basic approach to achieving maximum savings includes design to appropriate levels and incorporation of controls that reduce lighting when not used but provide for activation when needed in security identified locations.
Smart Energy’s Guidelines for providing effective lighting for safety and security:
- Horizontal- Illuminance This is the standard for assessing effective lighting primarily because many tasks are horizontal and the measurements are easy to make. However, this is less critical for security than other metrics such as vertical illuminance and uniformity.
- Vertical- Illuminance This is critical because one of the main security issues is identifying persons and vehicles and their movement which is best done by viewing their vertical surfaces.
- Uniformity/Shadows- This is important primarily to avoid dark areas where persons or objects may be hidden. Uniformity has also been found to be useful in enhancing video camera effectiveness.
- Glare- Lighting aimed in the wrong direction can cause glare that can adversely affect the ability of occupants and security personnel to identify persons and/or objects