Theoretical Analysis of the Lighting Calculation of Chromatic Color Louvered Ceiling Systems (Part I)

Optical Characteristics of One Duct Square Cell of Chromatic Color Louvers

Abstract

In previous papers the authors described a lighting calculation procedure for a room with an achromatic color louvered ceiling. However, we cannot use this procedure to calculate the luminous colors incident on horizontal illuminated surfaces and the true colors of walls of a room.
The authors thus started to study the lighting calculation procedure of chromatic color louvered ceiling systems in order to calculate not only illuminance and luminance but also luminous colors incident on horizontal illuminated surfaces and true colors of walls of a room.
The optical characteristics of chromatic color louvers of one duct square cell, namely, spectral efficiency, spectral changing rate (apparent spectral transmittance), and spectral radiant exitance and chromaticity of light on the undersurface of a louver are important factors for the lighting calculation procedure of chromatic color louvered ceiling systems.
In this paper, theoretical methods of those characteristics are proposed and their calculated values are given. The calculated values obtained by the theoretical analysis methods on the efficiency and the flux changing rate (apparent transmittance) of louvers and the chromaticity of light on the under surface of a louver are compared with the measured values. It is made clear that this theoretical method is effective.