Daylight optimization for green office building: a study of west facing window design and configuration

Abstract

Window placement and shading device configuration plays an important role when designing with daylight. In the tropical context, windows-especially on the west façade, can create unwanted illumination and induce glare. Excessive interior lighting can cause discomfort and stress amongst the users while poorly lit areas can have physical and mental consequences. Thus, the openings are to be configured as such that the interior can be naturally-lit while providing the optimum lighting for the required activities. In order to design a naturally-lit green office building, an experiment was conducted to determine the best opening configuration of a north-west facing building. For this purpose, a study model was constructed with adjustable slot-in louvres on the western side. A lux meter was used to measure the illuminance of the interior for different configurations of windows which varied according to the spacing, position, material and number of louvres. The daylight factor was calculated and the findings were found to be consistent with other literature on this topic. The results were established for several configurations which could be incorporated into design according to the design requirements. Finally, the findings were adapted and adjusted with respect to the building context and surroundings in designing the shading device for a green office building.