Evaluating appropriate roof shape and efficiency of wind tower and wind scoop for natural ventilation in residential buildings of Chabahar

Climatic design and attention to the discussions of sustainable architecture, which have been considered as the most important issues of contemporary architecture, have thousands of years of history, especially in Iran. Nowadays, climatic design is a rational reaction to the crises caused by the shortage of energy resources and increasing environmental pollutions which have been created by fossil fuels. In Iran, one of the climates that attention to its ecological conditions is vital for creation of thermal comfort and climate architecture is hot and humid climate which is facing high heat and humidity. In these regions, provision of ventilation and cooling by mechanical equipment requires to spend a great deal of energy and cost. In this paper, considering the discussions of climatic design in hot and humid climates of Iran, attempts were made to offer an appropriate physical mechanism (related to the optimal shape of roof and natural ventilation) to use natural ventilation in the residential buildings of Chabahar which are located in hot and humid climates and face the problem of heat and humidity. The research method used in this paper was descriptive analytical and computer modeling and numerical simulation by Autodesk Vasari software were applied to evaluate appropriate roof shape and efficiency of wind tower and wind scoop in the natural ventilation of residential buildings of Chabahar. Results of the computer simulations by Autodesk Vasari software were validated by ANSYS CFX software. The required information and data for this paper were collected from meteorological stations and valid documentation and library resources. Warm and humid air has a tendency to stay stagnating and, for ventilation, airflow must be used. In low-height and surrounded buildings where the facade of which is not encountered by appropriate airflow, roof has an essential role in the mechanism of natural ventilation. Furthermore, the airflow that crosses the roof is more stable and stronger. In this paper, through studying and modeling three kinds of roof (curve, steep, and flat) and their appropriate wind tower and wind scoop, appropriate roof shape and efficiency of wind tower and wind scoop in natural ventilation were evaluated and optimal physical mechanism of natural ventilation in the residential buildings of Chabahar (villas and apartments) was investigated. Finally, optimal form of the roofs (related to natural ventilation) and their wind tower and wind scoop were recommended to be used as the patterns of vernacular architecture in Chabahar city.