Why Day Light Harvesting System?
Daylight harvesting,
also called day lighting control or automatic daylight dimming or switching, uses a ceiling, wall or fixture-mounted light sensor to measure the amount of illumination at the task surface in the space or at the daylight aperture, then signals a switch or dimming ballast to adjust light output from the electric lighting system to maintain the desired level of illumination.
An effective daylight harvesting control system saves energy while being virtually unnoticed by occupants.
With a daylight harvesting control system, electric lighting is increased or decreased in direct or approximate proportion to the amount of natural light present, resulting in a minimum maintained illumination level in the controlled space. Daylight harvesting controls can be effective in virtually any type of facility where the lights operate much of the time and where a significant quantity of daylight is provided with windows and/or skylights.
Spaces with skylights and corridors, private offices and open cubicles near windows—particularly those with task lighting—are good candidates for daylight harvesting. If the entire space is uniformly skylighted, energy savings can accrue on the entire lighting load. More commonly, they apply only to the perimeter zone of a vertically glazed installation.
The result of daylight harvesting is energy savings. While the level of savings depends on the application characteristics, savings of 35-60+% have been demonstrated.
|
|
|
|
|
|
