TY - JOUR
T1 - Hydrometeorological determinants of green roof performance via a vertically-resolved model for heat and water transport
AU - Sun, Ting
AU - Bou-Zeid, Elie
AU - Wang, Zhihua
AU - Zerba, Eileen
AU - Ni, Guang Heng
N1 - Funding Information:
This work is supported by the National Science Foundation of China under Grant No. NSFC-51190092 and the US Department of Energy through Pennsylvania State University's Energy Efficiency Building Hub under grant No. DE-EE0004261 . We are grateful to Tsinghua Property Management Center and Princeton Facilities Department of Engineering for their assistance in field measurement campaign. We also thank the two reviewers for their constructive feedbacks.
PY - 2013/2
Y1 - 2013/2
N2 - In this study, the Princeton ROof Model (PROM) is developed, validated and used to simulate the hygrothermal dynamics of green roof systems. PROM is embedded within the framework of the Princeton Urban Canopy Model, with a multi-layer spatially-analytical heat transfer scheme and an improved hydrological module. The model is validated by comparing simulated surface temperature and soil moisture to the measurements at two experimental sites, one in Beijing, China and the other in New Jersey, USA. The results demonstrate that PROM is able to capture the diurnal cycle of roof temperatures and the soil moisture dynamics of green roofs with high accuracy. Driven by a 30-day summertime meteorological forcing from July 2001, PROM is used to investigate the green roof thermal improvement to the urban indoor and outdoor environments, compared to conventional roofs. The impact of green roofs is significant in reducing surface temperatures, and outdoor and indoor heat fluxes during this summer period. To quantify this thermal improvement, three indices related to surface temperature, outdoor heat flux and indoor heat flux, are introduced; and the dependence of these indices on hydrological and meteorological conditions is investigated. The results indicate that incoming solar radiation and medium layer moisture are the main determinants of the green roof performance.
AB - In this study, the Princeton ROof Model (PROM) is developed, validated and used to simulate the hygrothermal dynamics of green roof systems. PROM is embedded within the framework of the Princeton Urban Canopy Model, with a multi-layer spatially-analytical heat transfer scheme and an improved hydrological module. The model is validated by comparing simulated surface temperature and soil moisture to the measurements at two experimental sites, one in Beijing, China and the other in New Jersey, USA. The results demonstrate that PROM is able to capture the diurnal cycle of roof temperatures and the soil moisture dynamics of green roofs with high accuracy. Driven by a 30-day summertime meteorological forcing from July 2001, PROM is used to investigate the green roof thermal improvement to the urban indoor and outdoor environments, compared to conventional roofs. The impact of green roofs is significant in reducing surface temperatures, and outdoor and indoor heat fluxes during this summer period. To quantify this thermal improvement, three indices related to surface temperature, outdoor heat flux and indoor heat flux, are introduced; and the dependence of these indices on hydrological and meteorological conditions is investigated. The results indicate that incoming solar radiation and medium layer moisture are the main determinants of the green roof performance.
KW - Green roof
KW - Heat transfer
KW - Thermal performance index
KW - Urban Canopy Model
KW - Urban hydrology
KW - Urban microclimate
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U2 - 10.1016/j.buildenv.2012.10.018
DO - 10.1016/j.buildenv.2012.10.018
M3 - Article
AN - SCOPUS:84872397487
SN - 0360-1323
VL - 60
SP - 211
EP - 224
JO - Building and Environment
JF - Building and Environment
ER -