Set up of a test facility and the preliminary results for the visual and energetic performances assessment of smart windows

The use of large smart windows can help to improve the visual and thermal comfort inside rooms, as well as reduce the energy consumption of buildings. However, for the correct use of these new devices, their comprehensive characterization aimed at understanding their real performances from visual and energetic points of view is fundamental. For this reason, an experimental multiactivity test room was set-up for the visual and energetic on-site characterization of smart windows. Preliminary experimental measurements were performed with conventional double low-emittance glazings, with the aim of testing the acquisition system as well as validating and calibrating a virtual model of the test room realized in the dynamic simulation software TRNSYS 17. The TypeDLT, that allows for the direct interaction between TRNSYS and RADIANCE, was used and the reliability of the daylight simulation results was evaluated. The results show a good agreement between the simulated and experimental data. In terms of average daylight illuminances, values of the relative mean bias error equal to -0.7% and relative root mean square error equal to 16.6% were observed.