Performance Testing of Light Pipes in real weather conditions for a confrontation with Hemera

Daylight offers many possibilities. Its proper use is a major asset to develop the design, energy and environmental quality of a building but also improve the physiological and psychological conditions of the user. New emerging devices, offer the opportunity to improve visual comfort while, providing energy savings. The light pipes are considered as a part of these innovative devices. Existing semi-empirical models do not adequately transcribe the behavior of light pipes. The scientific objective of this study is to investigate the propagation of light within a real test-cell equipped with this device in real weather conditions. The aim is to better understand the role of each parameter (solar geometry, diffuse illumination, direct illumination, etc.). The results indicated a difference in light distribution within the test cell between the clear and overcast sky. We target new parameters to take into account in modeling the phenomenon.