TY - JOUR
T1 - Techno-economic and environmental performance assessment of radiative sky cooling-based super-cool roof applications in China
AU - Chen, Jianheng
AU - Lu, Lin
AU - Gong, Quan
AU - Lau, Wing Yin
AU - Cheung, Ka Ho
N1 - Funding Information:
The work is partially supported by Hong Kong Research Grant Council through General Research Fund ( PolyU 152184/17E ) and partially supported by HKSAR EMSD consultancy project (Ref# B-40143-1-2020).
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/10/1
Y1 - 2021/10/1
N2 - Integrating radiative sky cooling materials into buildings as a super-cool roof strategy can be one of the most direct pathways to implement this passive cooling technology. Accordingly, this study conducts comprehensive assessments on techno-economic and environmental performance of super-cool roof applications in China by combining model development, experimental validation, and numerical modeling. A novel radiative sky cooling-based super-cool roof model was developed in which the full spectral selectivity of radiative cooling materials can be incorporated and the model was experimentally validated with root mean square errors below 4.69%, verifying its good accuracy. Field experiments with reduced-size modeling buildings in a hot and humid region revealed that radiative cooling roofs can effectively reduce rooftop and indoor air temperatures for heat removal. The validated model was used for evaluating super-cool roof applications in ten typical cities of China. The results show that the super-cool roof can achieve the sub-ambient temperature of 2.6 °C under the solar radiation of 950 W/m2 in a hot and humid climate. Compared to the baseline of traditional roofs, the super-cool roof can reduce the maximum and average daytime roof temperatures by 24.8 °C (43.4%) and 10 °C (29%), respectively. Cumulative roof thermal transfer values can be decreased by 63.0–195.8 kWh/m2 (78.5–148.2%) in cooling seasons. The annual electricity saving in hot cities ranges from 42.9 to 97.8 kWh/m2 on average, in response to varying coefficients of performance. Super-cool roof induced maximum acceptable incremental cost falls within 34.6–64.7 $/m2 and 55.36–103.52 $/m2 for 5-yr and 8-yr simple payback periods, respectively. Besides, carbon emissions can be averagely reduced by 24.6–56.1 kg/(m2·yr). This study deeply elucidates the energy efficiency, economic feasibility and carbon neutrality potential of radiative sky cooling-based super-cool roof applications in China.
AB - Integrating radiative sky cooling materials into buildings as a super-cool roof strategy can be one of the most direct pathways to implement this passive cooling technology. Accordingly, this study conducts comprehensive assessments on techno-economic and environmental performance of super-cool roof applications in China by combining model development, experimental validation, and numerical modeling. A novel radiative sky cooling-based super-cool roof model was developed in which the full spectral selectivity of radiative cooling materials can be incorporated and the model was experimentally validated with root mean square errors below 4.69%, verifying its good accuracy. Field experiments with reduced-size modeling buildings in a hot and humid region revealed that radiative cooling roofs can effectively reduce rooftop and indoor air temperatures for heat removal. The validated model was used for evaluating super-cool roof applications in ten typical cities of China. The results show that the super-cool roof can achieve the sub-ambient temperature of 2.6 °C under the solar radiation of 950 W/m2 in a hot and humid climate. Compared to the baseline of traditional roofs, the super-cool roof can reduce the maximum and average daytime roof temperatures by 24.8 °C (43.4%) and 10 °C (29%), respectively. Cumulative roof thermal transfer values can be decreased by 63.0–195.8 kWh/m2 (78.5–148.2%) in cooling seasons. The annual electricity saving in hot cities ranges from 42.9 to 97.8 kWh/m2 on average, in response to varying coefficients of performance. Super-cool roof induced maximum acceptable incremental cost falls within 34.6–64.7 $/m2 and 55.36–103.52 $/m2 for 5-yr and 8-yr simple payback periods, respectively. Besides, carbon emissions can be averagely reduced by 24.6–56.1 kg/(m2·yr). This study deeply elucidates the energy efficiency, economic feasibility and carbon neutrality potential of radiative sky cooling-based super-cool roof applications in China.
KW - Carbon reduction
KW - Economic analysis
KW - Radiative sky cooling
KW - Super-cool roof
KW - Thermal and energy performance
UR - http://www.scopus.com/inward/record.url?scp=85113610126&partnerID=8YFLogxK
U2 - 10.1016/j.enconman.2021.114621
DO - 10.1016/j.enconman.2021.114621
M3 - Journal article
AN - SCOPUS:85113610126
SN - 0196-8904
VL - 245
JO - Energy Conversion and Management
JF - Energy Conversion and Management
M1 - 114621
ER -
