Natural ventilation is a simple and efficient method for nighttime passive cooling of buildings to improve residents’ comfort and reduce air conditioning. The effectiveness of ventilative cooling depends on the number and arrangement of the openings and local wind and temperature difference between indoor and outdoor. However, natural ventilation works only if cool air is available in the surrounding of a building and when this cool air finds a way to infiltrate indoors. In this paper, numerical models are used to simulate the penetration depths of cool air from the rural countryside into a residential area and to estimate the local cooling potential for an indoor environment of buildings. The results demonstrate that the country breeze is an important process to transport cool air during the night, but, due to the limitations in strength and depth, it is only efficient in the first 100–200 m of the outskirts. Based on numerical experiments for a standard room with two windows, an empirical relation was derived to estimate indoor cooling depending on local wind speed and local temperature difference. This relation was used to calculate individual nighttime room temperatures of all buildings in a residential area. It was found that indoor temperature follows the ambient temperature with a delay and cooling is only half as great as outside the building. In addition, the models are used to demonstrate the cooling effect of the country breeze by calculating for a decade the number of days in the summer months when nocturnal minimum room temperatures are below a given threshold.

中文翻译：

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自然通风对城市夏季夜间室内温度影响的数值研究

自然通风是建筑物夜间被动降温的一种简单有效的方法，可以提高居民的舒适度并减少空调。通风降温的效果取决于开口的数量和布置以及室内外的局部风和温差。然而，只有当建筑物周围有冷空气并且这种冷空气有办法渗入室内时，自然通风才会起作用。在本文中，数值模型用于模拟冷空气从农村进入居民区的渗透深度，并估计建筑物室内环境的局部冷却潜力。结果表明，乡村微风是夜间输送冷空气的重要过程，但是，由于强度和深度的限制，它只在郊区的前100-200 m有效。基于两窗标准房的数值实验，推导出了经验关系式，根据当地风速和当地温差估计室内制冷量。该关系用于计算住宅区内所有建筑物的个别夜间室温。结果表明，室内温度会延迟地跟随环境温度，并且制冷量只有建筑物外的一半。此外，这些模型还用于通过十年间计算夜间最低室温低于给定阈值的夏季月份的天数来证明乡村微风的冷却效果。基于两窗标准房间的数值实验，推导出了一个经验关系式，以根据当地风速和当地温差估计室内制冷量。该关系用于计算住宅区内所有建筑物的个别夜间室温。结果表明，室内温度会延迟地跟随环境温度，并且制冷量只有建筑物外的一半。此外，这些模型还用于通过十年间计算夜间最低室温低于给定阈值的夏季月份的天数来证明乡村微风的冷却效果。基于两窗标准房的数值实验，推导出了经验关系式，根据当地风速和当地温差估计室内制冷量。该关系用于计算住宅区内所有建筑物的个别夜间室温。结果表明，室内温度会延迟地跟随环境温度，并且制冷量只有建筑物外的一半。此外，这些模型还用于通过十年间计算夜间最低室温低于给定阈值的夏季月份的天数来证明乡村微风的冷却效果。该关系用于计算住宅区内所有建筑物的个别夜间室温。结果表明，室内温度会延迟地跟随环境温度，并且制冷量只有建筑物外的一半。此外，这些模型还用于通过十年间计算夜间最低室温低于给定阈值的夏季月份的天数来证明乡村微风的冷却效果。该关系用于计算住宅区内所有建筑物的个别夜间室温。结果表明，室内温度会延迟地跟随环境温度，并且制冷量只有建筑物外的一半。此外，这些模型还用于通过十年间计算夜间最低室温低于给定阈值的夏季月份的天数来证明乡村微风的冷却效果。