Wind catchers are natural ventilation systems attached to buildings in order to ventilate the indoor air. In order to design and evaluate the performance of wind catchers, as a natural ventilation system, an accurate CFD simulation of indoor airflow and outdoor wind flow is fundamental. It is widely known that there are a large number of computational parameters influencing CFD simulations. Consequently, comprehensive sensitivity analyses of the effect of these parameters on the simulation results are essential to provide guidance for the evaluation of a CFD study. According to the literature review carried out, a wide generic sensitivity study for the CFD simulation of natural ventilation in wind catchers is highly required. This paper presents a series of 3D steady RANS simulations for a generic isolated two-sided wind catcher attached to a room subjected to wind directions ranging from 0° to 90° with an interval of 15°. The CFD simulations are validated with detailed wind tunnel experiments. The influence of an extensive range of computational parameters is explored in this paper, including the resolution of the computational grid, the size of the computational domain, the turbulence model and the order of the discretization scheme.

Natural ventilation performance can be influenced by various factors, including facade treatments such as balconies. Balconies have been commonly incorporated into residential buildings for various purposes, yet the provision of a balcony as a passive design strategy to improve natural ventilation is not one of its common purposes. The objective of this study is to investigate the effect of balcony design on the natural ventilation performance of cross-ventilated high-rise apartments. This study uses Computational Fluid Dynamics (CFD) models to predict ventilation performance. CFD models are selected because of their accuracy, flexibility and ability to provide comprehensive data for the investigation. This study suggests that balconies in high-rise apartments could improve the ventilation performance of high-rise apartments, but that balconies can also have a negative impact on ventilation performance if not appropriately designed. Finally, this study suggests that balconies could improve the level of thermal comfort and indoor air quality of apartments by providing greater indoor air speed and better ventilation performance, respectively.

The implementation of green roofs or vegetated roof as a sustainable tool to mitigate the Urban Heat Island effect is relatively new in Malaysia. Although it has not been tested on an urban scale, many research findings have indicated that green roofs can contribute towards enhancing the environmental and aesthetical quality of the built environment. It was hypothesized that the low application of green roofs in the Malaysian construction industry is due to the lack of awareness, understanding and experience in its benefits especially among building practitioners. As a result, this research was initiated to determine the perception and understanding of Malaysian architects in green roofs implementation issues, as well as to identify their level of acceptance and readiness. This paper reviews practices and different research approaches in understanding the factors that influence architect’s perception towards the implementation of green roofs in the Malaysian construction industry. Architects were chosen as the only respondents due to their intensive involvement in the conceptualisation, planning, design and construction stage of a built environment project. Extensive literature review was conducted to explore past experiences in green roof implementation and to develop the theoretical framework for this research.