This study attempts to quantify thermal-stress abatement by tress, using the example of Bihar Museum at Patna, Bihar, India, where around 200 trees, though known as great solar heat attenuators, were felled to accommodate the newly-built museum. The study, with a focus on sensitivity analysis, compares two tree scenarios, at two input wind-speeds and seeks to identify the individual/synergetic effects of physical attributes of tree-morphology, background wind, etc., on cooling by trees, through simulations, using freely available model SkyHelios Pro. SkyHelios allows for the spatial/temporal analysis of the thermal changes at a point of time and space. The ‘area-mean’ rise in mean radiant temperature (T_MRT) is found 1.9 °C and in physiological equivalent temperature (PET) 1.1 °C, by 28 % trees-removal (area-wise), at noon at 0.5 m/s input wind-speed. T_MRT reduction by trees is found directly related to their canopy-size/cluster-density, and inversely to background wind-speed. PET reduction is directly related to the canopy-size/ cluster-density at lower wind-speeds and inversely at higher. The study is limited to daytime (noon) hours. Based on the detailed outputs from SkyHelios simulations, recommendations for passive cooling of urban outdoors in terms of tree size, layout-density, built-up morphology, and background wind-speed are formulated.

本研究试图以印度比哈尔邦巴特那的比哈尔邦博物馆为例，通过树木对热应力的减轻进行量化，该博物馆砍伐了大约 200 棵树（虽然被称为太阳热衰减器）以容纳新建的博物馆。该研究侧重于敏感性分析，比较了两种输入风速下的两种树木情景，并试图确定树木形态、背景风等物理属性对树木冷却的个体/协同效应，通过模拟，使用免费提供的模型 SkyHelios Pro。SkyHelios 允许对某个时间和空间的热变化进行空间/时间分析。平均辐射温度 (T _MRT)的“面积平均”上升) 的温度为 1.9 °C，生理等效温度 (PET) 为 1.1 °C，通过 28 % 的树木移除（按区域），中午在 0.5 m/s 输入风速下。发现树木的T _MRT减少与其冠层大小/簇密度直接相关，而与背景风速成反比。PET 减少与较低风速下的冠层尺寸/簇密度直接相关，而在较高风速下则相反。该研究仅限于白天（中午）时间。根据 SkyHelios 模拟的详细输出，制定了在树木大小、布局密度、建筑形态和背景风速方面的城市室外被动冷却建议。