Study On The Color Of Light Source And Energy Efficiency For Floodlight

For floodlight, the luminance and the color of the lighted substance depend not only on the power and the color of the light source, but also on the color of the lighted substance (the spectral reflectance of the surface), so, if we choose the optimum matching light source for the lighted substance in lighting design, we can get good result, and it is energy-saving.For floodlight, the radiant luminous flux of the shined plane is rightly the reflectance luminous flux of the surface, it can be abstained by integrating the visible region of the functions of spectral radiant flux, the ratio of spectral reflectance of the surface and spectral luminous efficiency. In this paper we defined a new word: the reflectance luminous efficiency ('η' in formulas), the unit ofηis lm/W.η=Φ/W , whereΦdenotes the luminous flux reflected by the shined plane from the light source, W denotes the power consumed by the plane.ηIndicates the matching efficiency of the light source and the lighted plane, the larger it is, the better the light source and the plane matches, the lesser the power it needs to light the lighted plane and the more the energy it saves.In order to calculate the reflectance luminous efficiency accurately, we must establish a scientific photometry system for urban floodlight first. This paper measures luminance of 114 urban floodlight cases in Shanghai, Tianjin, Chongqing, Chengdu, and Luzhou. Basing on the metrical results, finds that the luminance in all cases are more than several cd/m2, they are in the photopic vision. So this paper uses V (λ) as the computational foundation.This paper gathers abundance of spectral radiant flux of various universal single light sources (for example PZ, LSG, HG, HR, HGG, RGB, KNG, GGY, DDG, NG, NGG, NTY) and light-mixing sources, analyses the spectral reflectance character of materials in urban floodlight (for example wood , stone, metallic plate, concrete wall, various paint wall), calculates reflectance luminous efficiency of CIE recommended 14 standard color boards for every sources, namely,η(source, plane). Through methods of division compare and chromatism classification, Compares the calculated reflectance luminous efficiency we can find the optimum energy-saving light source for every lighted planes, then Lighting designers can choose the best energy-saving lighting source for every cases.