Evaluating the impact of aperture design on natural ventilation in modern Maltese condominiums

Abstract

This dissertation explores how aperture design influences natural ventilation in Malta’s high-density residential buildings, responding to the growing need for sustainable and comfortable living. Focusing on modern apartment blocks, the study investigates how variations in window orientation, shape, quantity, and front-to-rear aperture ratios affect air exchange and thermal comfort. Using DesignBuilder software and three representative case studies, the research follows a stepwise simulation: analysing orientation, then window design, and finally aperture ratios. Key performance metrics include Air Changes per Hour (ACH), operative temperature, Cooling Degree Days (CDD), and ventilation-related heat transfer (kW). In this study, the ventilation rate in kilowatts reflects heat displacement by natural airflow as calculated in DesignBuilder—not energy consumption. Results show that west-facing façades, multiple landscape-shaped windows, and higher front façade aperture ratios yield the best ventilation. An inverse correlation between operative temperature and ACH illustrates the cooling benefit of effective aperture placement. Findings suggest that even small design changes can significantly reduce reliance on mechanical cooling, offering practical insights for architects, engineers, and policymakers working toward climate-responsive residential design in Malta.