Design and Evaluation of Passive Solar Ventilation in Urban Courtyards

Thesis Abstract

Urban environments often face significant challenges related to heat accumulation and inefficient ventilation, particularly in densely built areas where traditional architectural forms hinder natural airflow. Passive solar ventilation offers a sustainable solution by utilizing architectural design strategies to enhance air movement and thermal regulation without reliance on mechanical systems. However, the integration, effectiveness, and optimization of passive ventilation strategies within urban courtyards remain under-explored, especially considering varying climatic and contextual factors. This study aims to design, implement, and evaluate passive solar ventilation techniques specifically tailored for urban courtyards, with the ultimate goal of improving thermal comfort and reducing cooling energy demands. The research objectives focus on assessing the influence of courtyard orientation, shading, and opening configurations on airflow rates and indoor thermal conditions, as well as developing evidence-based design guidelines for architects and urban planners. The research employs a mixed-methods approach, combining quantitative experimental analysis with qualitative assessments. The quantitative component involves the installation of scaled physical models and full-scale pilot interventions in two selected urban courtyards within the city of Berlin, with the sample comprising measurements from ten different courtyard configurations each, totaling 20 cases. Data collection instruments include anemometers, thermocouples, and thermal imaging cameras to record airflow velocities, temperature differentials, and solar radiation levels during different seasons. The qualitative aspect involves semi-structured interviews with architects, urban planners, and residents, generating insights into contextual preferences, perceived comfort, and practical constraints. Data analysis will utilize computational fluid dynamics (CFD) simulations to predict airflow patterns and thermal performance, complemented by statistical analyses such as regression analysis and ANOVA to examine the relationships between courtyard design variables and thermal outcomes. Thematic analysis will interpret interview transcripts to contextualize the quantitative findings. Expected findings suggest that optimal courtyard orientation (especially east-west alignment), strategic shading, and adjustable openings significantly enhance natural ventilation and thermal comfort, with CFD models corroborating field measurements. The study anticipates identifying key design parameters that maximize airflow rates, reduce indoor temperatures by at least 2 degrees Celsius during peak summer conditions, and improve occupant comfort indices. These results are expected to contribute to the theoretical understanding of passive ventilation in urban courtyards, integrating principles from the Comfort Theory and Scholarly Ventilation Models, thereby advancing existing knowledge on climate-responsive architecture. This research's primary contribution lies in providing a comprehensive, empirically validated framework for passive solar ventilation tailored to urban courtyard contexts, addressing a significant gap in the literature concerning the practical application and performance of such systems. The findings will inform architectural design guidelines and urban planning policies aimed at enhancing sustainability and climate resilience in densely populated areas. The main conclusion emphasizes that strategic courtyard design, grounded in empirical evidence and theoretical insights, can substantially improve natural ventilation outcomes, leading to energy savings and enhanced thermal comfort for building occupants. Recommendations include adopting specific courtyard spatial configurations, incorporating adjustable shading elements, and integrating CFD-based design assessments early in the architectural process. Future research directions suggest exploring the influence of climate variability and integrating passive ventilation strategies with other sustainable features such as green roofs and reflective surfaces to further optimize urban microclimates.