| 摘要: |
| 城市绿色基础设施在缓解城市热岛
方面有良好效果。其中，在建筑壁面绿化类型
中，攀援植物绿化表皮具有成本低、占地少、
冠层可控的特点，应用潜力较大。在应用上，
绿化表皮与建筑过渡空间的结合日渐增加。
过渡空间作为开敞空间，易受外部热环境的
直接影响，而绿化表皮的遮阳与蒸腾降温作
用提供了调节热环境的可能。因此，本文聚焦
于绿化表皮对过渡空间的热环境调节作用，
通过实测调研分析其调节效果。方法上，考察
一幢被绿化表皮包裹的外廊建筑，采用动态
测量法，用动态测量工具包在遮挡与非遮挡区
间进行阶段性测量，对比两者的热环境变化。
与非遮挡区相对比，绿化表皮可降低太阳总
体辐射70.2% ~ 88.3%（84.75~391.35 W/m 2 ），
空气温度与平均辐射温度（MRT）值降幅为
3.8 ℃与11.4 ℃，相对湿度增幅为10.6%，风
速降幅达2.6 m/s。综合计算后，通用热气候指数（UTCI）值降幅为2.0 ℃。实测显示了绿化表皮具有良好的遮阳作用，对过渡空间的热环境有
良好的调节效果，但对风环境有一定影响。因此，绿化表皮的种植与布置策略仍有进一步优化的
潜力 |
| 关键词: 绿化表皮 过渡空间 热环境 UTCI |
| DOI：10.13791/j.cnki.hsfwest.20200510 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（52078214）；
国家建设高水平大学公派研究生资助项
目（201606150060） |
|
| Effects of Green Façade on Thermal Comfort in Transitional Spaces |
|
LIN Hankun,XIAO Yiqiang
|
| Abstract: |
| Urban green infrastructure has been promoted as a countermeasure to the urban
heat island (UHI). As one of the green wall systems, green fa?ades (GFs), which are mainly
constructed vertically by climbing plants, present significant potentials in applications due
to the properties of low cost, low occupation of land, and controllable foliage layers. In
applications, integrations of GFs and building transitional spaces are increasing in recent years.
However, the thermal environment of a transitional space is easily affected by the outdoor
environment due to the openness or semi-openness. To solve this problem, GFs provides
possibilities to improve the thermal comfort in the transitional space via the shading and
evaporation cooling effects. Thus, this paper intends to investigate the optimizing performance
of GFs on thermal environment in a transitional space of a dormitory building in Munich,
Germany.
A methodology named transitional measurements, which shifts a toolkit between the
shaded and unshaded area periodically in order to compare different effects on thermal
environment rapidly and sensitively, was introduced in field measurements. The objects
of observations are global solar irradiation (Ga) and thermal comfort indices. The field
measurements were separated into two typical summer. A moveable toolkit with sensors was
set alternately in the middle of the corridors with the distance of 0.7 m to the facades and the
height of 1.1 m on the 1st floor (shaded with the GFs) and the 3rd floor (unshaded). On 10th
July, 2018, the toolkit was just set on the west fa?ade and recorded the Ga data, then on 11th
July, 2018, it was shifted from east fa?ade to west fa?ade after 13:00 and collected two groups
of thermal indices data to compare.
Results of the first day reveal that comparing to the unshaded area, the global solar
irradiation was reduced by 70.2%~88.3% (84.75~391.35 W/m 2 ). On the second day, the Max.
ambient temperature (Ta), mean radiant temperature (MRT), and universal thermal climate index
(UTCI) were reduced by 3.8 ℃, 11.4 ℃, and 2.0 ℃. However, Max. wind flow velocity (Va)
also reduced by 2.6 m/s. Ta and UTCI values were at a higher level when the Va values were at
a lower level before 13:00. It could be explained that the indices followed the variation of the
weather data, which show that the cloud cover ratio (CCR) was lower and the solar irradiation was higher in the morning, respectively, the measured Va increased in the afternoon when the test points were set on the orientation facing to the
main wind direction of north-west.
Ave. Tg, Ta, MRT, and UTCI of shaded area reduced by 0.9 ℃, 0.8 ℃, 1.4 ℃, and 0.9 ℃ on the east fa?ade from 9:00 to 13:00, relatively,
which increased by 2.2 ℃, 0 ℃, 2.7 ℃, and 0.8 ℃ on the west fa?ade from 13:00 to 17:00. Ave. Va of shaded area reduced by 0.1 m/s (east) and
0.7 m/s (west). Results reveal that the GFs present potential of optimizing the human thermal comfort indices in the transitional spaces during the
higher Ta and lower Va period. With the wind flow became stronger in the afternoon, the UTCI was lower in the unshaded than the shaded area.
Considering the values variated slowly when the test position changed periodically, the average values of different indices may not reflect
the trend of the variation sufficiently. Thus, a further comparison of the haft hour data is added. Result reveals that the indices including Tg, Ta,
MRT, and UTCI followed the decreasing trend during the shaded period. The average reduction of MRT and UTCI in the shaded period is 11.4 ℃
and 2.0 ℃. Through shifting the test positions between the shaded and unshaded area and following the sun path, the measurements reflected the
shading effect significantly.
Comparing to the UTCI category, results presented that 52.4% of the UTCI values were at the “no thermal stress level (9~26 ℃)” and
39.4 % of which were at the “moderate thermal stress level (26~32 ℃)”. All the transitional space in the test project presented a thermal comfort
condition during the measurement period.
Results indicated that the GFs have potentials for thermal comfort optimization in the transitional space, respectively, have weaken effects
on wind flows. Thus, layouts and distributions of GFs still need to improve in future studies. |
| Key words: Green Façade Transitional Space Thermal Environment UTCI |
