TY - JOUR
T1 - Influence of plant and soil layer on energy balance and thermal performance of green roof system
AU - He, Yang
AU - Yu, Hang
AU - Ozaki, Akihito
AU - Dong, Nannan
AU - Zheng, Shiling
N1 - Funding Information:
The study has been supported by the China National Key R&D Program ‘Solutions to heating and cooling of buildings in the Yangtze River region’ (Grant No. 2016YFC0700305-02 ) and the China Sponsorship Council through the “ National high-level University Graduate ” program (Grant No. 201506260026 ). In addition, the authors want to express gratitude to Shanghai Zhonghui Eco-Technology Co., Ltd. for the support of green roof modules in the experiment.
PY - 2017/12/15
Y1 - 2017/12/15
N2 - This paper aims to make clear the effects of two important parameters, namely thickness of soil layer and leaf area index of plant layer, on green roof energy and thermal performance. Based on a coupled hygrothermal transfer model validated by field experiments in Shanghai area, energy balance of plant and soil layer is analyzed. Then 18 cases are simulated for different combinations of soil thickness and leaf area index, the results show that soil thickness has a significant effect on long term thermal performance of green roof in both summer and winter, while the effect of leaf area index is only great in summer. Compared with the hypothetical case without evaporation and transpiration, it is found that evaporation of soil layer makes a greater contribution in summer but a less one in winter compared with insulation effect of soil layer. For plant layer, shading is the main cooling way of roof deck while transpiration plays a minor role. Finally, based on the simulation results of long-term thermal performance, two new indexes are proposed to evaluate the relative thermal characteristic of green roof. And the influences of soil thickness, leaf area index and evapotranspiration on the two indexes are analyzed respectively.
AB - This paper aims to make clear the effects of two important parameters, namely thickness of soil layer and leaf area index of plant layer, on green roof energy and thermal performance. Based on a coupled hygrothermal transfer model validated by field experiments in Shanghai area, energy balance of plant and soil layer is analyzed. Then 18 cases are simulated for different combinations of soil thickness and leaf area index, the results show that soil thickness has a significant effect on long term thermal performance of green roof in both summer and winter, while the effect of leaf area index is only great in summer. Compared with the hypothetical case without evaporation and transpiration, it is found that evaporation of soil layer makes a greater contribution in summer but a less one in winter compared with insulation effect of soil layer. For plant layer, shading is the main cooling way of roof deck while transpiration plays a minor role. Finally, based on the simulation results of long-term thermal performance, two new indexes are proposed to evaluate the relative thermal characteristic of green roof. And the influences of soil thickness, leaf area index and evapotranspiration on the two indexes are analyzed respectively.
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U2 - 10.1016/j.energy.2017.08.064
DO - 10.1016/j.energy.2017.08.064
M3 - Article
AN - SCOPUS:85032179978
SN - 0360-5442
VL - 141
SP - 1285
EP - 1299
JO - Energy
JF - Energy
ER -