Effect of Window Glazing on Colour Quality of Transmitted Daylight

Abstract

In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The spectral transmittance data of different window glazing types are taken from the International Glazing Data Base (IGDB), which is maintained by Lawrence Berkeley National Laboratories (LBNL). The study showed that the CIE CRI does not always seem to be the suitable method to predict the colour quality of daylight in building for particular situations. However, in the context of this study, the prediction of colour rendering properties of window glazing by other metrics such as Colour Quality Scale (version 9), Memory CRI, Ra,D65 (adjusted CRI metric with D65 as the reference illuminant) performed better. For most of the daylit situations inside the building, the chromaticity difference criterion was not met. Judging the colour quality of such situations requires different method.

Keywords

• Colour rendering
• Colour quality
• CIE CRI
• Window glazing