Evaluation of annual luminous performances of skylights using luminous intensity distribution

摘要

The dimensioning of a zenithal lighting generally obeys the two following constraints: the daylight factor must be compatible with the practised activity and the solar gains must be controlled. Concerning the first point, abacuses make it possible to define the order of magnitude of the surface of opening to be implemented. When the skylights are different from those of the abacuses, those lead to very approximate results. On the basis of the analogy between skylights and luminaires for interior lighting, a photometric tool for the characterization of these skylights was developed to produce the photometric data (luminous intensity distribution) under overcast sky (for the calculation of the daylight factor) and with multizones sky (for the analysis of the annual luminous performances). The objective of this tool is double: to provide a help to the design of skylights and to evaluate the performances of these skylights once in situation.