Active daylighting

Abstract: Daylighting systems make daylight illuminance possible, and the development of prototype daylighting systems can provide more efficient daylight illuminance. The purpose of this article is to review the development and performance of prototype daylighting systems in the last decade. The passive and active daylighting systems are listed separately and divided into the four categories by the presence and absence of hybrid. Each prototype daylighting system was evaluated in terms of cost and daylight performance and as well as their novel optical design. We evaluated the architecture and daylighting principles of each system by reviewing individual prototype daylighting systems. The cost of prototype systems still poses a challenge to development. How to use passive or active systems in different environments and whether or not electrical lighting assistance is needed is a controversial issue. However, active daylighting systems equipped with solar tracking systems are still mainstream. This research is a valuable resource for daylight researchers and newcomers. It is helpful to understand the advantages of various prototype daylighting systems and commercial daylighting systems that have been developed for many years; moreover, it is also possible to know the research directions suggested by the prototype daylighting systems. These will be of further use in developing innovative and better daylighting systems and designs.

Abstract: A daylighting system for structures consisting of a solar energy collector means including a modified Cassegrainian optical system, a means of moving said collector means to an attitude tracking the sun's position in the sky during daylight hours, a heat separation means for removing heat from the concentrated beam of sunlight and for applying said heat to other uses, and one or more hollow members each comprising a reflective internal surface for distributing the sunlight inside said structure.