In recent years, much attention has been given to the analysis of windows with shading systems. If the solar and thermal performance of these systems can be accurately predicted, than building designers would be better able to include shading as an effective solar control device.

In previous studies, a theoretical model that predicts the solar performance of louvered shading layers has been developed. The purpose of the present work is to validate those models through the use of a Broad-Area Illumination Integrating Sphere (BAI-IS). Such a device is capable of measuring the spectral directional-hemispheric properties of an inhomogeneous material or system (such as a Venetian blind). The experiments showed that the zero thickness slat assumption caused some error when the slat and profile angles are nearly aligned.

Units: Dual