Monitoring and simulation of visual and photo-biological properties of daylight-redirecting systems

We previously developed a Camera-Like Light Sensor (CLLS) to record an image or a video using high dynamic range imaging technique. The device was equipped with customized filters for adapting the camera’s spectral sensitivity to both photopic and circadian sensitivities (the latter is used to refer to non-visual effects of light). Here, we used the CLLS to monitor distributions of luminance and circadian weighted radiance over time in two test rooms, equipped with different daylight re-directing systems: venetian blinds (VB) and optical louver systems (OLS). In addition, a computer simulation of circadian weighted irradiance (Eec) was performed for the two test rooms by using the software tool RADIANCE. For this purpose, circadian irradiance was computed at different positions corresponding to the gaze directions of a seated office worker. Overall, the simulation of Eec was similar between the two rooms, but the room with VB showed a significant decline of simulated Eec deeper in the room, which was not the case for the room with OLS (p