Experimental evaluation and ray-tracing modelling of the energy and optical properties of glazing systems with selective coatings

Transparent materials play an important role on energy and comfort requirements of buildings; in the present work, a series of optical measurements has been carried out with a spectrophotometer on several kind of glazing, equipped with different coatings. A theoretical model was used to predict the optical properties of multilayered coated glazing systems, starting from characteristics of the single components. This model and a ray tracing approach (implemented with a commercial simulation code) were validated through experimental measurements, showing a satisfactory agreement and revealing that, for high thickness and diffusive glazing systems, the theoretical simulations are to be preferred, since the spectrophotometer analyses could bring to wrong results. The passage to simulation tools permits a wider investigation of all different panes combinations, with a little effort; it is therefore possible to change many variables such as glass thickness, type of coating, type of glass and coating position, at the aim of fulfilling to requirements of every single application.