All Sky Model as a standard sky for the simulation of daylit environment

It is important to apply natural light effectively for low energy consuming daylighting design. A reliable standard sky that expresses real sky luminance distributions is required for the simulation and evaluation of daylit environment. Any applicable standard sky, however, has never found that shows accurately actual states of daylight. In order to establish a suitable sky model that can represent all the sky luminance distributions from clear sky to overcast sky continuously, the authors propose a sky luminance distribution model named “All Sky Model”. The detailed descriptions about All Sky Model for the simulation and evaluation of daylit environment are explained in this paper.