Theoretical modelling and experimental evaluation of the optical properties of glazing systems with selective films

Transparent spectrally selective coatings and films on glass or polymeric substrates have become quite common in energy-efficient buildings, though their experimental and theoretical characterization is still not complete. A simplified theoretical model was implemented to predict the optical properties of multilayered glazing systems, including coating films, starting from the properties of the single components. The results of the simulations were compared with the predictions of a commercial simulation code which uses a ray tracing technique. Both models were validated thanks to several measurements carried out with a spectrophotometer on single and double sheet glazings with different films. Results show that both ray tracing simulations and the theoretical model provide good estimations of optical properties of glazings with applied films, especially in terms of spectral transmittance.