Effect of Roller Shades on Chromaticity and Colour Rendering Performance of Transmitted Daylight

Abstract

Several studies have focused on the performance of roller shades in terms of glare, outdoor vision, daylight availability and energy performance. Currently, other parameters linked to visual amenity, such as chromaticity and colour rendition, are becoming relevant. When solar radiation passes through a window, it changes its spectral composition due to the presence of the solar shading system and the glazing. Against this background, the present study focuses on the spectral transmittance of eleven woven screen fabrics and its influence on the chromaticity and colour rendition. Results show that dark-coloured woven screen shades provide higher correlated colour temperature (CCT) values (range 6470 K - 6479 K) and therefore would produce “cooler” visual environments, while light-coloured woven screen shades provide lower CCT values (range 5210 K - 5644 K) creating “warmer” visual environments. Regarding colour rendering metrics, the light transmitted through all the studied woven shades shows excellent colour rendition. Finally, it is concluded that the combined analysis of optical properties, spectral data and its impact on parameters that determine the quality of lighting in an interior space enables an understanding of woven screens performance, which results in the possibility of taking appropriate decisions when selecting woven shades.

The Necessity for Multi-Spectral Simulations of the Indoor Non-Visual Luminous Environment: A Simplified Annual Approach

“…However, the effect of shading on the non-visual aspects of the space considerably depends on the type and spectral characteristics of the shading device. For instance, using textile screens as an example, Villalba et al [62] demonstrated that the selection of the shade of the textile influences the CCT of the transmitted daylight, with darker screens resulting in higher CCTs. On the other hand, Potočnik and Košir [53] investigated the correlation between DGP, horizontal task illuminance and melanopic illuminance through in situ experiments in an office equipped with a spectrally neutral (white) opaque roller blind.…”