Core Sunlighting Systems

Solar Canopy for Core Daylighting
Abstract: 

Core sunlighting systems deliver sunlight deep into multi-story building cores, where daylight is not available through skylights or windows. An effective core sunlighting system offers physiological and psychological benefits to occupants while dramatically improving the quality and color rendering of lighting, reducing lighting electricity use up to 75%, and reducing electricity loads during peak demand periods.

CLTC collaborated with the University of British Columbia (UBC) on demonstrations of core sunlighting systems that have since emerged on the market. Core sunlighting systems integrate energy-efficient electric light sources, such as LEDs, with advanced daylighting technologies. The systems use a combination of moveable and fixed mirrors to collect sunlight into a light distribution channel lined with a high-reflectance material. Integrated electric light sources controlled by photosensors are automatically activated when sunlight levels are insufficient and dimmed or shut off when ample daylighting is available.

In July 2013, a laboratory at the University of California, Davis was retrofitted with a SunCentral System. SunBeamers were mounted on the rooftop to collect sunlight and redirect it as a collimated beam through an existing SunShade structure already mounted to a window of the building. The SunShade blocks heat gain and glare from reaching the window below it while transmitting the sunlight collected at the rooftop level into 30-foot luminaires designed to integrate sunlight and LED lighting. A SunCentral System was also recently installed at the USDA’s Farm Service Agency building in Davis, CA.

CLTC will collaborate with UBC on the development of testing protocols to monitor the system’s performance over a solstice-to-solstice period, including an equinox and the summer and winter solstices. Researchers will then evaluate the system’s annual performance in terms of its impact on energy and peak electricity demand, lighting quality, and occupant comfort. CLTC will also evaluate the cost effectiveness of core sunlighting systems, based on performance data collected, and assess the potential for reduced product and installation costs through commercial production.

This RD&D work builds upon information gathered through past field tests of the SunCentral Core Sunlighting System at the Veterinary Medicine Facility N-2 Building on the UC Davis campus.

Principal Investigator: Konstantinos Papamichael

Staff Contact

Konstantinos Papamichael, Ph.D.

Professor Emeritus, Department of Design