Development of an electric-driven smart window model for visual comfort assessment

Smart windows, especially those electric-driven, represent one of the most advanced technologies for controlling solar radiation. For a correct use, it is necessary to understand their real behaviour through in-situ measurements on full-scale application as well as calibrating and validating visual simulation models capable of predicting their performances. In this paper, the preliminary results of current research activities aimed at developing simulation models of electric-driven full-scale glazing are presented. The research activities started with the assessment of the visible solar transmittance as a function of light incident angle through in-situ measurements; different models, with related values, of the visible solar transmittance were considered. For each simulation model, the corresponding transmittance value was set in the RADIANCE “trans” material model and the simulated illuminance values, for a defined acquisition point of a test-facility, were then compared with the experimental data. Finally, for each model, indoor luminance distributions were reported considering a typical office seating position. Preliminary results, based on the in-situ measurements approach, highlighted a sufficient accuracy for one of the models adopted; further analyses are needed in order to upgrade the simulation models available and assess the effective performances of these windows.