Experimental glass optical data of new glazing systems to improve energy savings

Transparent spectrally selective coatings on glass or polymeric substrates have been recently proposed to optimize daylighting and energy performances of glazing systems. Although a wide choice of these materials is available, the experimental and numerical characterization of their properties is still not complete. Optical measurements on several single and double sheet glazings with different solar-control coatings have been carried out with a spectrophotometer. The aim is to define optimal combinations of glazings and coatings to realize energy efficient multi-sheet systems. Transmittance and reflectance measurements have been carried out referring to different angles of incidence of daylight. The paper presents the first experimental results and a discussion on the influence of various parameters (such as glazing thickness, kind of coating, angle of incidence) on the energy performances of glazing systems. A comparison has been carried out using experimental data to build multisheet glazings and data extracted from WINDOW software. Simulations were performed with the hourly simulation program IENUS. The program was developed to assess the building energy demand with different kinds of climatic data and of daylighting