Paper Conference

Proceedings of BSA Conference 2022: Fifth Conference of IBPSA-Italy


Investigating the Performance of Different Window Opening Styles for Single-Sided Wind-Driven Natural Ventilation Using CFD Simulations

Akshit Gupta, Annamaria Belleri, Francesco Babich

Abstract: Natural ventilation can be an effective means of providing healthy and comfortable indoor environments while minimizing energy consumption. However, the use of diverse types of windows and control strategies usually leads to different indoor local thermal conditions. Previous studies have focused on indicators of ventilation effectiveness, but too little is known about the spatial variations of thermal comfort generated by different window opening styles. CFD is a powerful numerical modeling technique to compare the air distribution within a room, and therefore to evaluate the performances of different type of window in terms of delivered thermal comfort and indoor air quality (including local effects). Thus, the aim of this research is to investigate the effectiveness of diverse type of window, such as bottom-hung, horizontal pivot and top-hung fanlight for single-sided wind-driven natural ventilation. In this study, two wind speeds and two wind-window angles were investigated, for two weather conditions typical for the region of South Tyrol, Italy. In this study, thermal comfort was evaluated based on standards EN ISO 7730 and ASHRAE Standard 55. Using transient RANS CFD simulations, the performance of different window configurations for the different boundary conditions were numerically evaluated. The boundary conditions, geometrical simplifications, grid-independence tests, discretization, and basic principles for a transient simulation were chosen based on previous studies and then tested to ensure the correct modelling of a wind-driven natural ventilation flow. The results show 25 %-200 % higher incoming airflow when the wind enters at an acute angle as compared with perpendicular wind. Furthermore, the horizontalpivot window reports a 39 % higher incoming airflow when compared with bottom-hung window style, while the draught risk in winter conditions was similar for both.
Pages: 137 - 144