Quantifying impacts of wind speed and urban neighborhood layout on the infiltration rate of residential buildings

Abstract

Urban neighborhood layouts affect wind flow patterns and infiltration rates in the built environment and ultimately, local thermal comfort and energy consumption of buildings. This study uses Computational Fluid Dynamics (CFD) to quantify infiltration rates in low-rise residential buildings. The validated simulation results using the experimental data propose k-ω SST turbulence model to simulate outdoor airflow. Three urban plan area density with four common types of urban morphologies including (i), (ii) Cases A and B: regular and staggered cubical buildings, respectively and (iii), (iv) Cases C and D: street canyon with parallel and vertical wind flow, respectively, are examined. The simulation results indicate that wind speed does not have a decisive role in determining the infiltration or exfiltration phenomenon, and it only is able to increase or decrease the rates of them. The absolute infiltration rate for wind speeds of 1, 4, and 8 m/s is of the considerable scale of 1:2:12 in the all investigated building rows and layouts. The urban layouts findings demonstrate that decreasing the compactness of the buildings reduces the negative pressure gradients. Besides, if the leakage area is parallel to the dominant wind flow, the exfiltration rate is barely a function of the wind speed.