This study proposed a novel approach for naturally ventilated buildings to address the challenges of rising temperatures and increased urban heat island effect in African cities. Existing research often overlooks the performance of combined wind and buoyancy-driven systems in the context of climate change. This research introduced a novel chimney-enhanced cross-ventilation configuration that effectively combined both wind and buoyancy effects for optimal performance. By conducting CFD simulations and detailed building energy simulations, the study aimed to quantify the contributions of these driving forces to assess the performance of the proposed innovative ventilation approach in various urban settings, and analyze its adaptability to future climate scenarios. The cross-ventilation system showed superior performance to a single-sided ventilation solution with identical opening areas. The proposed solution achieved airflow rates up to 20 times higher than that of the single-sided alternative, even in urban environments shielded by tall buildings, due to its ability to effectively harness both wind and stack effects. Consequently, this allowed an improvement in thermal comfort, shown by the higher fraction of occupied time within the thermal comfort range, in comparison with single-sided ventilation. Furthermore, the cross-ventilation system could significantly decrease energy use by mechanical cooling systems by up to 31 %, when compared to the single-sided solution. Finally, the use of night cooling further increased energy savings, and significantly reduced peak mechanical cooling thermal loads. Overall, the chimney-enhanced cross-ventilation system is a promising solution for improving indoor environmental quality and energy efficiency in buildings in African cities, since it is particularly well-suited for the climate change-induced challenges in that continent. The findings of this study can inform the design and implementation of sustainable building practices, promoting the adoption of natural ventilation strategies to mitigate the impacts of climate change.

中文翻译：

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非洲城市幼儿园烟囱增强型对流通风系统的制冷能力评估


本研究提出了一种自然通风建筑的新方法，以应对非洲城市气温上升和城市热岛效应增加的挑战。现有的研究往往忽视了在气候变化背景下风力和浮力驱动系统的性能。这项研究引入了一种新颖的烟囱增强交叉通风配置，该配置有效地结合了风和浮力效应以实现最佳性能。通过进行 CFD 模拟和详细的建筑能源模拟，该研究旨在量化这些驱动力的贡献，以评估所提出的创新通风方法在各种城市环境中的性能，并分析其对未来气候情景的适应性。交叉通风系统的性能优于具有相同开口区域的单侧通风解决方案。由于该解决方案能够有效利用风和烟囱效应，因此即使在被高层建筑遮挡的城市环境中，所提出的解决方案也能实现比单侧替代方案高 20 倍的气流速率。因此，与单侧通风相比，这允许提高热舒适性，这体现在热舒适范围内的占用时间比例更高。此外，与单侧解决方案相比，对流通风系统可以显著降低机械冷却系统的能耗，最高可达 31%。最后，夜间冷却的使用进一步提高了能源节约，并显著降低了峰值机械冷却热负荷。 总体而言，烟囱增强型对流通风系统是改善非洲城市建筑物室内环境质量和能源效率的一个有前途的解决方案，因为它特别适合应对非洲大陆气候变化引发的挑战。这项研究的结果可以为可持续建筑实践的设计和实施提供信息，促进采用自然通风策略来减轻气候变化的影响。