Natural Ventilation and Indoor Air Quality in Domestic School Building: CFD Simulation and Improvement Strategies

Abstract

Natural ventilation is a process of replenishing used air from the interior environment with fresh outer air without the use of mechanical equipment. This project aims to investigate the feasibility and performance of implementing natural ventilation in dilapidated classroom designs of actual geometry. Computer models of an existing classroom were created using SOLIDWORKS based on real-scale building floor plans, while the same software was applied to compute flow simulation studies to visualise the airflow pattern, temperature distribution, relative humidity, and the thermal comfort level of occupants in the classrooms. Estimated climate parameters were input in the simulation process to illustrate better the effect of hot and humid climate conditions in Malaysia towards the thermal comfort level of occupants. In this project, a visualised wind tunnel was created to simulate the prevailing wind source that supplies wind to the designed classroom, and the airflow pattern across the designed building was analysed. From the initial simulation results, it was discovered that the airflow into the classroom is uneven, whereby some locations in the building are experiencing extremely low wind breeze, which eventually affects the comfort level of occupants in the room. On the other hand, an internal analysis focusing on the interior comfortability of the classrooms was applied to examine the thermal comfort condition while using the naturally ventilated classrooms. Recommendation optimisation approaches such as the louvre angle and introduction of a windcatcher was presented in this project to improve the natural ventilation performance of the designed classroom.