Modelling the optical and thermal properties of complex glazing: overview of recent developments

• Published in: Solar energy Vol. 69; no. 1; pp. 1 - 13
• Main Authors: Rosenfeld, J.L.J, Platzer, W.J, van Dijk, H, Maccari, A
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2001
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/S0038-092X(01)00028-7

The recently completed ALTSET project was part of the European Commission’s Standards, Measurement and Testing programme. Its objective was the development of European standard test procedures for the determination of angular-dependent light and total solar energy transmittance for complex glazings and integrated shading elements. In parallel to the development of test procedures, models to predict the properties of a variety of complex glazings were developed and validated. We review the progress made during this collaborative programme. Models have been developed for a wide range of complex glazings, including those incorporating solar control films, transparent insulation and both fixed and variable blinds. The models are based on the concept that a complex glazing can be represented by a stack of layers, each layer representing one of the component elements of the glazing. If the optical and thermal properties of each layer are known, methods are available to calculate the corresponding properties of the stack. Used with some caution, the models are able to predict the luminous and total solar energy transmittance to an accuracy comparable to that obtainable experimentally. The models are suitable for integration into building energy simulation tools. One area requiring further investigation is an improved model for scattering components.