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What You Need to Know About Daylight Harvesting for Commercial Buildings from Acuity


Daylight harvesting is a commonly used lighting control technique required by most energy codes. These zones are normally a group of lights close to a window or skylight where we expect a high amount of natural light to be present and the full use of artificial lights aren't necessary to maintain an adequate light level. To understand how daylight harvesting works, it might be good to understand the difference between the terms daylight and daylighting. Daylight is radiation emitted by the sun, including the radiation scattering effects of the atmosphere. Daylighting is the practice of utilizing daylight in buildings to provide view and illumination.

Utilizing daylight for ambient and task lighting can have significant energy benefits by reducing the amount of electric lighting and associated HVAC loads. Daylighting in commercial buildings can reduce lighting electricity use by as much as 38%. To get the reduced energy benefits, you need to deploy lighting controls that adjust electric lighting based on available daylight. Daylight harvesting considerations span the whole building life cycle, from the selection of the building site, through architectural and interior/lighting design, to building construction, commissioning and operation. Managing daylight penetration based on outdoor and indoor environmental conditions can greatly increase daylight harvesting benefits, not only energy benefits but also psychological, physiological and biological benefits.