Dynamic analysis for daylight availability in high-density urban area

This study describes a dynamic analysis method to investigate daylight availability in high-density urban area. In contrast to traditional static concept based on Daylight Factor, this method introduces Daylight Coefficient and Perez sky luminance function, which can be used to dynamically analysize the annual daylight level profile. Daylight Coefficient on the outside surfaces of buildings has been calculated by DaySim, a package using Radiance algorithm. Also, Sky Luminance Distribution comes from annual solar gains through Perez’s sky model function. Accordingly, integrating Daylight Coefficient and sky luminance distribution would get illuminace values across the outside surfaces. The annual illuminance profile of there surfaces is a significant indicator for daylight levels in buildings.
Three typical built layouts in current high-density Chinese city have been modelled and simulated. The solar radiation data in the simulation are derived from the weather file (2005) of Beijing and Shanghai, which represent different weather zones (II and III) in China and both have plenty of high-density lots. The proposed methodology can help urban and building designers evaluate the possibilities of using natural lighting in high-density area from the early conceptual design stages.