Daylight distribution and the associated heat gain of a commercial building with curtain wall façade under different degrees of obstruction are studied. A new metric ‘useful daylight illuminance’ (UDI) is applied to analyze the time varying illuminance distribution on a work plane. The solar irradiance obtained from the daylighting simulation is input to a two-node thermal model for energy simulation. The indoor air temperature profile, cooling and heating load requirement and the associated electrical energy consumption based on a typical coefficient of performance (COP) are reported.
2010 The Illuminating Engineering Institute of Japan