Any work space operational during the day has an option to use natural day light for the operational purpose instead of the artificial lights but human response to alternate sources or limited access to the lighting manual controls hinders the energy efficiency and cost savings potential. Switching off the lights in an unoccupied space or during the availability of glare free day light could save up to 50 % of the lighting energy. Automated lighting controls are available in the market under two broad categories – 1) standalone systems (occupancy sensor or day light sensors), and 2) Network control systems (time schedule, central monitoring etc).
These systems use time switches or photocells to switch lights. Photocells can monitor the level of useful daylight and turn off in rows adjacent to windows.
Network control systems
A Network control system is termed as intelligent system which uses one or more central computing network to control the lighting operational requirement in indoor and outdoor lighting through manual inputs or programmed inputs. Network control systems respond to changing conditions as per the building functional requirement or schedule. Systems that give more control can be time based, e.g. switching off in lunchtime. Centralized systems rely upon dedicated computers to control either the building services or just the lighting. In case of building services a software program controls the various services like lift, fire alarms, lighting, air conditioning and other equipment’s uses information from transducers and sensors in the building.
Following key steps are required during the design and execution stage for effective implementation of lighting control strategy-