Temperature and cooling demand reduction by green-roof types in different climates and urban densities: A co-simulation parametric study
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AbstractThis paper presents a parametric study on the effect of four green-roof types on outdoor/indoor temperature and cooling demand under four different climates and three urban densities using co-simulation approach with ENVI-met and EnergyPlus. Results reveal an outdoor nighttime warming effect of not more 0.2 °C which is most obvious with the semi-extensive while the outdoor and indoor cooling effect ranges between 0.05–0.6 °C and 0.4–1.4 °C, respectively depending on the green-roof type, urban density and time of the day. These daytime temperature reductions also vary per prevailing climates and follow this order: hot-dry, hot (or warm)-humid, and temperate which can be explained by the interplay between solar intensity/air temperature and relative humidity between the regions. In a hot-humid region, the evaporative cooling potential of greenery is dampened when compared to hot-dry region. This is also true for region with low solar intensity and humidity like the temperate region. In terms of cooling demand reduction, 5.2% was observed in hot-dry climate on the hottest day of the year with full-intensive green-roof while the least saving of 0.1% was found with semi-extensive green-roof in temperate climate. In general, for both outdoor temperature and cooling demand reduction, semi-intensive green-roof was found more effective than its full-extensive counterpart while the higher spatial green-roof is most important for indoor temperature reduction irrespective of the leaf density of the greenery. Therefore, the intent of green-roof installation should be a determining factor for the type and spatial extent to be implemented.
All Author(s) ListK.W.D. Kalani.C. Dahanayake, Edward Ng, Cheuk Lun Chow
Journal nameEnergy and Buildings
Year2017
Month6
Day15
Volume Number145
PublisherElsevier
Pages226 - 237
ISSN0378-7788
eISSN1872-6178
LanguagesEnglish-United Kingdom
KeywordsCooling demand, Green-roofs, Cooling effect, Urban densities, Climate zones, Co-simulation

Last updated on 2020-24-05 at 23:57