In investigating the daylighting of skylights, it can be assumed that they are behaving as luminaries — having a major role in the lighting features of the interior space. To be able to analyze the daylighting characteristics of various skylights and to be able to measure and follow the quality and quantity of transmitted illumination — it is necessary to understand the exact role of the skylight as they are being an important and dominant part of the overall daylighting system. There is not enough precise information on these daylighting systems, and because of this, it is difficult to predict precisely the quality and quantity of illuminance and the light distribution in the interior, and it is difficult to precisely design and accurately dimension the actual daylighting system to meet all the necessary functional, structural and daylighting requirements. The skylights — being the luminaries of the daylighting system — will distribute and modify the external illumination in the interior space:

• the positioning and geometrical characteristics of skylights precisely defines a portion of the exterior space — and practically this portion of the exterior space will be acting as the luminarie of the interior space,

• the different structural parts of the skylights will determine the illumination and light distribution characteristics in the interior space.

The geometry and positioning of the skylights together with their structural characteristics will result the illumination and light distribution in the interior space. The resulted illumination quantities and — distribution can be measured and analyzed in the reference plane of the interior space.

Input — Sky

daylighting system (skylight + lightwell)

Output

E ref. plane = f (interior geometry) Figure 2: Daylighting System I/O