Passive cooling assessment of natural ventilation by windcatchers for enhancing thermal comfort and indoor air quality in European schools

Abstract

Windcatchers have drawn increasing attention in contemporary architecture due to sustainability and environmental concerns. Despite many recent studies on windcatchers, there is no comprehensive study on the European climate context. To address the existing gap, this research takes the opportunity to explore and evaluate the passive cooling potential, thermal comfort, and IAQ performance of windcatchers in educational spaces across the capitals of 15 Western European countries. Furthermore, to address the lack of passive cooling indices in the current literature and provide in-depth insights into passive cooling performance, two new indices are defined: the “Passive Cooling Thermal Benefit (PCTB)” index and the “Indoor Heat Load Tolerance (IHLT)” index. CFD results demonstrate that windcatchers can efficiently satisfy the Adaptive model of ASHRAE 55, where indoor temperatures in all cities, except Rome and Madrid, remained lower than the maximum suggested by the standard. In addition, the calculation of passive cooling indicates a range from 0.7 kW in Rome to a maximum of 11.4 kW in Dublin. The impact of the windcatcher performance on IAQ parameters was also promising, as the flow rate of supplied fresh air in all cases exceeded 122 L/s, meeting the minimum recommendation of ASHRAE 62.1. A similar pattern was observed for CO₂ concentrations. Finally, this study concludes that the windcatcher can be an efficient natural ventilation strategy for providing thermal comfort and IAQ, supporting the sustainability targets of the European Union.