Evaluation of different solar control strategies for a commercial building in moderate climate.

Windows have an important role in buildings both for daylighting, thermal comfort, and energy consumption. The aim of the paper is to evaluate the influence of glazings in energy saving for non-residential buildings, by considering advanced solar control solutions such as spectrally selective glasses. A multifunctional building was investigated and a dynamic thermal model was implemented by means of EnergyPlus software. The energy demand was estimated in different climatic conditions both for heating and cooling, by considering three Italian cities (Perugia, Milan, and Palermo). In order to evaluate the influence of windows, different kind of glazings were selected: conventional double-glazing with low-e coating and solar control double glass windows. In particular, three commercial solutions from different manufacturers were chosen, considering the latest generation of technology. Optical measurements were carried out on the samples using a spectrophotometer working in the 300-2500 nm range, the visible and solar transmittance were calculated according to EN 410 Standard and the experimental data were used as inputs in the thermal model. Finally, also the effects of blind systems on the façades were evaluated and the results were compared to solar control glazings performance. Results showed that not only the thermal transmittance but also the solar transmittance of glazings has a large effect on thermal comfort and energy demand, depending on the climate conditions. The spectrally selective solar control glazings showed significant benefits, especially in summer, due to their combined low solar transmittance and low emissivity properties, without penalizing the natural light transmission.