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In tropical climate, there is actually abundant quantity of daylight but yet to be utilised. The excessively high and unpredictable external illuminance could cause non-uniform indoor illuminance distribution and visual discomfort. In order to improve daylighting quality in contemporary high-rise open plan offices, proper design of internal shading should be investigated. A base model was derived from previous case studies for simulation using Radiance. Various venetian blinds, vertical blinds and light shelves were configured for the experiment. Daylight factor (DF) was evaluated for quantitative performance; work plane illuminance (WPI) distribution and vertical plane luminance ratio were investigated for qualitative performance. The findings demonstrated that generally blinds were not a good potential for daylight utilisation but good in reducing luminance contrast. Light shelves improved performances in DF and WPI distribution but increased the luminance contrast. Hence, integrations of light shelves and partial venetian blind (45° closed) were proposed as the effective designs for all orientations. The highest improvements of 31.8% in WPI distribution and 66.7% in luminance ratio were achieved for south and east orientations, respectively. This paper demonstrates that with proper internal shading design, effective daylighting depth can be significantly improved from typically used 2.5 H rule of thumb to 3.6 H.

In a tropical climate, passive cooling is difficult to achieve with respect to mass housing design. A good house design keeps the indoor environment favorable and comfortable during most of the year without the use of any mechanical devices. Terraced houses are typical examples with low comfort problem that need particular consideration. Low air velocity and high air temperature are experienced during the daytime and the wind effect is not well captured, especially in the single sided ventilation. Use of natural ventilation has been increasingly examined as an energy-efficient means to provide thermal comfort as well as a healthy indoor environment. This paper discusses the validation of Computational Fluid Dynamic (CFD) results and the measurement of thermal comfort in Malaysia's single storey terraced houses. The thermal environment and comfort conditions were investigated using field measurement and CFD technique. Validation of CFD FloVent was carried out through the comparison of field measurements. Comparison of the results between simulations and measurements illustrated a good agreement. The simulations were performed on a selected day in a one-year climate condition. The results indicated that the design of single storey terraced houses is not effective in providing natural ventilation for achieving thermal comfort. The microclimate condition surrounding the terraced house indicated very low wind speed. Therefore, modification of the natural ventilation mechanism using a solar chimney as induced ventilation needs to be manifested and evaluated.

As daylight is dynamic, there is no one common solution for all scenarios. Understanding of sky conditions is the fundamental to effective daylighting. It is more critical in tropical climate where the sky is predominantly intermediate with inconsistent presence of direct sunlight (DSL). Thereby, daylighting performances of several light shelf configurations were experimented with physical scaled model under actual tropical sky conditions. External illuminance and indoor work plane illuminance (WPI) levels were measured concurrently in a reference model and a test model for comparisons. Daylight ratio or daylight factor and WPI uniformity ratio were computed for analysis. From the results, different optimum cases were identified for various sky conditions. Light shelves performed the best under intermediate sky with DSL from low angle. The highest improvement in WPI at deep room area and WPI uniformity were 24.87% and 364.96%, respectively. The performances of light shelves under overcast sky were better than light shelf under intermediate sky without DSL. This paper concluded that designing light shelf by responding to changeable sky conditions and DSL is more crucial than considering the façade orientations. Dynamic light shelf was proposed to configure the optimum cases for each tropical sky conditions.

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