The project on Improved Daylight Performance of Tubular Daylighting Devices (TDDs) sought to develop, demonstrate, and help to commercialize new diffuser elements that redirect a significant portion of the emitted daylight towards the ceiling and precisely filter and spread the rest, producing a direct/indirect luminaire effect. The result would be to increase the acceptance of TDD daylighting systems by introducing systems with luminance ratios that are closer to the accepted norms for interior spaces.

Project team: CLTC and Solatube International, Inc.

Breakthrough concept designs were developed by Solatube, and prototypes were built. The units did not completely meet the team performance metrics. Further development of the designs and prototype testing will be necessary. The final report is under development.