Air pollution remains a major global health concern, contributing to millions of premature deaths annually. Poor indoor air quality (IAQ) is strongly associated with sick building syndrome (SBS), which can lead to various health problems and reduced workplace productivity. This study examines the role of trickle vents as a passive component in natural and hybrid ventilation systems aimed at improving IAQ and occupant comfort. Two types of factory-produced trickle vents were tested in a controlled climatic chamber under systematically varied indoor–outdoor pressure differentials, generated using a blower system. Airflow measurements revealed a strong relationship between pressure difference and vent performance. Differences between the two vent types were largely due to variations in cross-sectional areas, influencing airflow resistance and pressure drop. Although neither vent achieved the required ventilation rates for standard conditions, their integration into hybrid systems, particularly in combination with mechanical exhaust fans, was found to significantly enhance potential airflow. The findings underline both the challenges and opportunities in achieving effective ventilation, especially in upper building floors where natural driving forces are reduced. This work contributes to the understanding of passive ventilation components and their potential to support healthier, more sustainable indoor environments.