Extract

Passive systems for natural ventilation design have the ability to control the mechanism of wind in order to improve indoor conditions. Many of the previous studies have focused on analyzing different parameters and passive systems to predict the indoor natural airflow. Building parameters and systems are important in determining the feasibility of natural ventilation design. In an urban scale, traditional buildings in the north of Iran used the passive cooling system which is called breezeway (Nafas Kesh) in order to make buildings more breathable and cool the internal spaces. This study focuses on the performance of the earth duct connected to a double brick wall (breezeway) system and the impact of different breezeway width on indoor natural ventilation. This system was simulated by computational fluid dynamics (CFD) program. A model with fixed earth duct height of 0.01 in reduced scale and different breezeway widths of 0.008 m and 0.02 m and 0.04 m in 1:200 reduced scale was analyzed. Results show that model with fixed earth duct height of 0.01 m connected to breezeway widths of 0.08 m and 0.02 m decreases indoor volume flow rate 10% and 4%, respectively. While the model with breezeway width of 0.04 m increases indoor flow rate slightly equal to 2%. In a model with breezeway widths of 0.008 m and 0.02 m Indoor mean air velocity decreases 30% and 10%, respectively. Although in model with breezeway width of 0.04 the mean
air velocity increases 3%.

Keywords: Natural ventilation, breezeways, earth ducts, CFD.

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