Proceedings right light 2nd european conference on energy-efficient lighting. Directing diffuse light : a new and simple method for improved daylighting performance. European Conference on Energy-Efficient Lighting [2, 26-29 Set. 1993, Arnhem].

Sick, Friedrich.

1993

530
CIENA

By its nature, diffuse daylight may be effectively used only in the close neighbourhood of the daylight opening e.g. the window. This is due to the fact that only a small portion of the diffuse luminous flux enters at angles close to the surface normal. For an isotropic hemisphere in front of the daylightopening, the radio r of the luminous flux within a certain angle 2 T to the total diffuse luminous flux is r=1-cos T. This function is illustrated in figure 1.For instance, if T = 10°, r is calculated to 1.52. ABSTRACT. . It is shown in the paper that this ratio may be well exceeded using a simple geometric principle. Although the total luminous flux is substantially decreased, the directed luminous flux may be in the order of one magnitude higher than the equivalent portion of an isotropic hemisphere. In case of anisotropic hemispheres, the advantages might be even larger. INTRODUCTION. BASIC PRINCIPLE. APPROACH. ANALYSIS. TECHNICAL SOLUTIONS. CONCLUSION.

Presenta diagrs. y gráfs.

GENERAL; ILUMINACION NATURAL; GRADO DE APROVECHAMIENTO; ASPECTOS TECNICOS;