Radiative cooling ventilation improvement using an integrated system of windcatcher and solar chimney

Abstract

The escalating crisis of non-renewable energy sources is a critical universal concern due to its adverse impact on global warming. Addressing this situation calls for strategically implementing passive cooling techniques in building design. Radiative cooling (RC), an emerging method, offers potential due to its capacity to integrate seamlessly with complementary passive strategies. This study endeavors to combine one of these ventilation techniques from ancient Persian architecture, known as the windcatcher with RC in the form of an innovative roof radiative cooling (Windcatcher-RC) with a solar chimney (SC), yielding two configurations based on the arrangement of these constituents, namely SC/Windcatcher-RC and SC + Windcatcher-RC. These designs underwent rigorous assessment within identical situations and were applied to single- and two-story buildings. This Comparative evaluation aimed not only to discern the most optimal cooling and ventilation strategy for each architectural typology but also to validate the proposed passive cooling system’s efficacy. The case studies were simulated utilizing Computational Fluid Dynamics (CFD) through the ANSYS Fluent 2021 software. The results indicate that, for single and two-story buildings, the favorable approaches are SC/Windcatcher-RC and SC + Windcatcher-RC, respectively, owing to their attainment of 8.3 and 7.8 Air Changes per Hour (ACH) in terms of ventilation, alongside their capacity to average indoor temperature reduction of approximately −3 °C during peak hours as thermal performance. This system is also able to save 60% cooling energy and 80% of the ventilation energy during peak hours in a warm and arid climate. Furthermore, the effects of a wall opening on ventilation and thermal efficiency were examined.