An investigation on airflow simulation study on urban scale for passive ventilation strategies

Abstract

Energy efficient building design has emerged by an active contribution of simulation and analysis tools on design stages. Especially in recent years, the concept of Building Information Modelling (BIM) has introduced a platform that incorporates the entire building lifecycle into the designers during the design phase. The program delivers an opportunity to acquire and manage the building in different design scenarios that have more efficient and more optimized solutions. The oil embargo imposed by OPEC countries in the 1970s emphasized the importance of going for energy consumption, and after these dates, the buildings were forced to be more conservative regarding both heating and cooling costs. To reduce energy consumption reduction of cooling and heating needs and to design more efficient HVAC devices has become a priority. The use of passive ventilation systems is also one of the essential inputs to energy expenditure in structure. In this respect, the obstruction of air flow is considered a critical factor as much as the design of the structure. The condition of surroundings and relations of prevailing wind in a layout of neighboring buildings are curial factors in passive ventilation design. The aim of the research presented here is that passive ventilation must initiate at the urban scale and then be introduced to building scale. Therefore, to be able to use passive ventilation in a building, it is first necessary to layout a city that respects the prevailing wind directions, and speeds then consider the calculation for a structure that can efficiently utilize the winds as natural ventilation element. As a case study, two different textured neighborhoods of Antalya that is a hot and humid city is selected for analyses on building height and the solid-void ratio of city context. The methodology of the research is first, created the mass models in the existing buildings and then, airflow simulation utilized to study the prevailing wind directions and speed derived from national meteorology database. The result of air circulation simulation maps in two neighborhoods in different urban contexts are evaluated and discussed in the paper. The study argue that running any passive design or a green design on only a building scale will underestimate the situation; it needs to be handled on the urban scale. The research aims to contribute to the work that will be done in this direction.