Luminance Calculation Model and Modified Coefficient of Building Nightscape
YANG Chun-yu,LIANG Shu-ying and ZHANG Qing-wen
DOI:10.11835/j.issn.1674-4764.2012.01.014
Received ,Revised , Accepted , Available online July 01, 2015
Volume ,2012,Pages 71-75
- Abstract
The illumination computational formula recommended by the International Commission on Illumination (CIE) does not adapt to the modern construction materials with mixed reflection characters. In order to find a new luminance computational method adapting to the modern construction materials and to save building energy and control urban nightscape luminance, 30 frequently-used construction materials with respect to various directions in photometric laboratory were measured. Then the luminance modified coefficient K(i,β) was figured out, and analysed the connection of reflection luminance and atmospheric attenuation in the process of divergence of light. The K(i,β) and viewing distance, light kinds, luminaire use, material cleanliness, maintenance condition of lighting system as modified coefficient was adopted to amend the computational formula of CIE, and then a new calculation model is derived. Through calculating and comparing, the luminance value of the new calculation model is one-third as much as that of the traditional one.