Prediction of natural ventilation performance through a comparative study of interior void and courtyard void designs in two-storey urban row houses

Natural ventilation is an important passive design strategy for improving indoor environmental quality while reducing dependence on energy-intensive mechanical cooling systems. However, in dense urban contexts, two-story row houses often face airflow limitations due to compact layouts, narrow facades, and limited openings. This study aims to predict and compare the performance of two natural ventilation strategies, namely interior void and courtyard void. The research methodology uses three analytical approaches: Convex Space and Computational Fluid Dynamics (CFD) simulations to evaluate airflow circulation patterns, velocity distribution, and indoor temperature. The study was conducted on a two-story row house prototype at Summarecon Residence, Bekasi, with a floor plan area of 6 × 14 m (84 m2 per floor). The position and dimensions of the inlet and outlet were made the same in each scenario, while external parameters such as average wind speed and outside temperature in 2024 were used in the simulation. The results show that the courtyard void produces better ventilation performance with an average wind speed of 2.17 m/s and a temperature of 33 °C, compared to the interior void, which only reaches 1.17 m/s with a temperature of 33.43 °C. In addition, the area near the courtyard had a maximum wind speed of 6–7 m/s, while the interior void had 5-6 m/s. These findings provide evidence-based recommendations on the importance of integrating passive ventilation strategies in row house design.