Passive systems in traditional houses in Middle East areas: Solutions and effects of natural ventilation

The Middle East area, has a specific culture and habits, enhanced by adaptation to the environment and local climate through the traditional building constructions where typical design, structures and materials represent the basis for passive strategies. In these hot-dry regions, many traditional houses consist of compact design structures with internal courtyard where the effects of thermal inertia and natural ventilation can be well exploited. This paper focuses on the analysis of passive techniques used in some houses located in Damascus old city, which are renowned for their distinctive adaptability. These traditional houses have a unique structure consisting of two levels: the first floor built with heavy mass stones, while the second has light mass (timber and mud). The presence of an internal courtyard on which several rooms of different size overlook, give rise to an appreciable natural ventilation (single side or cross ventilation) through a proper opening of windows. Based on experimental data (air temperature, air velocity) acquired during a summer period in a traditional house, dynamic simulation for different type of structures and opening are performed in order to investigate the influence of natural ventilation on reducing internal temperature and evaluate comfort conditions using ASHRAE standard. Results also suggest strategies to optimize passive techniques to reduce energy needs.