A study of solar radiation daylight illuminance and sky luminance data measurements for Hong Kong

Solar radiation, outdoor illuminance and sky luminance data are important for accurate cooling load determinations and daylighting evaluations. Systematic data measurements are regarded as the most effective and accurate method of setting up reliable databases. This paper describes solar data measurements made at the City University of Hong Kong and reports some of the general findings. The daily and hourly average values of solar radiation and daylight illuminance are computed and presented using graphical methods. Sky luminance distributions for different typical sky conditions including overcast, clear and intermediate are studied and described. Implications for energy-efficient building designs are discussed.