A computer-based procedure has been developed for calculating the illuminance factor from a diffusing window illuminated by parallel or diffuse light, taking into account its non-uniform luminance. This paper compares the small errors which arise when the luminance distribution of the panel is derived from the measured photometric properties of one of a series of five reference materials with the much larger errors which result when the panel is regarded as a uniform diffuser.
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References
1.
Hopkinson R., Petherbridge P. and Longmore J.Daylighting (London: Heinemann) (1966)
2.
Krochmann J. and Lindner J.Tageslichtbeleuchtung fürFenster mit lichtstreuenden Gläsern Lichttechnik23(3) 131 (1971)
3.
Boyd I.H.The calculation of natural lighting from windows illuminated by clear skies and direct sunlightProc. 23rd Annual Congress of the South African National Committee on Illumination, Johannesburg, 1976 R/BOU 918 (Pretoria : National Building Research Institute, CSIR) (1982)
4.
Boyd I.H.The calculation of the illuminance factor from translucent rooflights illuminated by sunlightProc. 32nd Annual Congress of the South African National Committee on Illumination, East London , 1985 R/BOU 1337 (Pretoria: National Building Research Institute, CSIR) (1986)
