Seasonal and diurnal thermal performance of a subtropical extensive green roof: The impacts of background weather parameters

Lilliana L. H. PENG, Chi Yung JIM

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Most studies explored green-roof thermal effects on a few hot summer days based on short-term monitoring data. Few studies investigated the seasonal and diurnal patterns of thermal performance and associated weather effects. This research aims to address the following two questions: (1) how green-roof thermal performance varies with different season and time; and (2) to what extent can thermal performance be predicted by background weather parameters? A retrofitted extensive green roof was established on the top of a railway station in subtropical Hong Kong. Monitoring data covering a two-year period, one year before roof greening and one year after, were collected and analyzed. Results indicated notable seasonal and diurnal patterns of green-roof thermal performance. It exhibited cooling effects in spring, summer and fall, but warming effects in winter. The cooling effects were more pronounced in summer than spring and fall, on sunny days than rainy and cloudy days, and in nighttime than daytime. Air temperature, relative humidity, wind speed, solar radiation, and soil moisture could explain 83.6%-86% of the thermal effects' variation. The multiple-regression models based on the five weather variables established in this study provide an uncomplicated and direct approach to predict the thermal performance of similar extensive green roofs in subtropical areas. Copyright © 2015 by the authors.

Original languageEnglish
Pages (from-to)11098-11113
JournalSustainability (Switzerland)
Volume7
Issue number8
DOIs
Publication statusPublished - 14 Aug 2015

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Roofs
roof
weather
performance
temperature effect
Thermal effects
summer
monitoring
Cooling
cooling
Monitoring
Soil moisture
Solar radiation
multiple regression
parameter
Hot Temperature
relative humidity
German Federal Railways
solar radiation
Hong Kong

Bibliographical note

Peng, L. L. H., & Jim, C. Y. (2015). Seasonal and diurnal thermal performance of a subtropical extensive green roof: The impacts of background weather parameters. Sustainability, 7(8), 11098-11113. doi: 10.3390/su70811098

Keywords

  • Green roof
  • Thermal performance
  • Weather effects
  • Seasonal effect
  • Temporal pattern