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http://dx.doi.org/10.12813/kieae.2013.13.5.067

Reduction Potential for Thermal Load by Extensive Green Roofs  

Kim, Yeon Mee (Korea Institute of Construction Technology)
Nam, Mi A (Korea Institute of Construction Technology)
Jang, Dae Hee (Korea Institute of Construction Technology)
Kim, Hyeon Soo (Korea Institute of Construction Technology)
Kim, Hyun Ok (Korea Aerospace Research Institute)
Publication Information
KIEAE Journal / v.13, no.5, 2013 , pp. 67-77 More about this Journal
Abstract
Based on the increasing demand for a solution to reduce thermal load, extensive green roofs have great opportunity for application to existing roofs due to their light-weight and easy maintenance. The present study delivers data regarding thermal behavior and heat reduction potential in relation to vegetation coverage between green roof types. 1) In the hottest hour in a day, green roofs showed considerable potential to mitigate heat load in roof environments, which can be up to $10^{\circ}C$ difference. 2) Compared to conventional cement roofs, the extensive green roofs only have a slight potential to cool the air over green roofs. By statistical analysis of linear regression, green coverage has little to do with the reduction of air temperature; the cooling effect was proven only in nighttime. 3) Green roofs act as an insulating roof membrane, the inner substrate of green roofs remained cooler than cement roof surfaces in the daytime, but in the nighttime the green roofs generally were warmer than the cement roof surfaces. 4) The variable of vegetation coverage resulted in no significant difference in thermal behavior in the air, but had the greatest effect in keeping the substrate cool in the daytime. The high vegetation coverage also hindered the rapid cooling of the substrate in the nighttime, and therefore was warmer than other measured temperatures. In order to draw a clear conclusion to combat urban heat island effect with extensive green roofs, the experiment needs to be applied on a larger scale.
Keywords
Urban heat island; Vegetation coverage; Thermal load; Extensive green roofs;
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  • Reference
1 Alcazar SS & Bass B(2005) Energy performance of green roofs in a multi storey residential building in Madrid. University of Toronto.
2 Bousselot J, Klett JE, Koski RD(2011) Moisture content of extensive green roof substrate and growth response of 15 temperate plant species during dry down. HortScience 46(3): 518-522.
3 Brenneisen S(2003) Oekologisches Ausgleichspotenzial von extensiven DachbegrueungenBedeutung fuer den Arten- und Naturschutz und die Stadtentwicklungsplanung. Doctoral dissertation, University of Basel, Switzerland.
4 Del Barrio, EP(1998) Analysis of the green roofs cooling potential in buildings. Energy and Buildings, 27, 179-193.   DOI   ScienceOn
5 Desjarlais AO, Zaltash A, Atchley JA (2010) Thermal Performance of vegetative roofing system. Proceedings of 25th RCI International convention. http://www.ornl.gov/sci/ees/etsd/btric/pdfs/ThermalPerfof VegetatedRoofSystems_Mar2010.pdf.
6 Getter KL, Rowe DB (2006) The role of extensive green roofs in sustainable development. HortScience 41(5): 1276-1285.
7 Jim CY, Tsang SW (2011) Ecological energetics of tropical intensive green roof. Energy and Buildings 43: 2696-2704   DOI   ScienceOn
8 Kim HS, Kang JS, Pyon HS (1999) A study on the development of roof-planting system and its thermal performance. Architectural Research 15(3):127-134.   과학기술학회마을
9 Koehler M, Schmidt M, Grimme FH, Laar M, Paiva VLA, Tavares S (2002) Green roofs in temperate climates and in the hothumid tropicsfar beyond the aesthetics. Environ Manag Health 13(4): 382391. DOI:10.1108/09566160210439297.   DOI   ScienceOn
10 Lee DK, Yoon SW, Sh SH, Jang SW (2005) The effect of temperature reduction as infludneced by rooftop greening. J. Korean Env. Res. & Reveg. Tech 8(6): 34-44.
11 Littell RC, Henry PR, Ammerman CB (1998) Statistical Analysis of Repeated Measures Data using SAS Procedures. Journal of Animal Science 76: 1216-1231.   DOI
12 Liu K, Baskaran B (2005) : Thermal performance of green roofs through field evaluation. NRCC-46412. Proceedings for the First North American Green Roof Infrastructure Conference. http://archive.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc46412/nrcc46412.pdf.
13 Liu K, Minor J (2005) Performance evaluation of an extensive green roof. In: Greening rooftops for sustainable communities. Washington, DC, pp.111.
14 Nardini A, Andri S, Crasso M (2012): Influence of substrate depth and vegetation type on temperature and water runoff mitigation by extensive green roofs: shrubs versus herbaceous plants. Urban Ecosyst 15: 697708. DOI 10.1007/s11252-011-0220-5.   DOI
15 Oh SH (2007) The analysis of temperate reduction effect of an extensive green roof. Master Thesis. Seoul National University.
16 Oke, TR (1987) Boundary layer climates. New York.
17 Park EJ, Kang KI, Nam MA (2010) Green roof strategy for mitigating the urban heat island effect. Policy research 2010-25, Gyeonggi Researc Institute pp.1-168.
18 Wanphen S, Nagano K (2009) Experimental study of the perfor mance of porous materials to moderate the roof surface temperature by its evaporative cooling effect. Building and Environment 44: 338-351.   DOI   ScienceOn
19 Simmons MT, Gradiner B, Windhager S (2008) Green roofs are not created equal: the hydrologic and thermal performance of six different extensive green roofs and reflective and non-reflective roofs in a sub-tropical climate. Urban Ecosyst. DOI 10.1007/s111252-008-0069-4.
20 Unger, J. (2004). Intra-urban relationship between surface geometry and urban heat island. Review and new approach. Climate Research, 27, 253e264.   DOI
21 Wong NH, Chen Y, Ong CL, Sia A (2003) Investigation of thermal benefits of rooftop garden in the tropical environment. Building and Environment 38: 261-270.   DOI   ScienceOn
22 Wong NH, Cheong KKW, Yan H, Soh J, Ong CL, Sia A (2003): The effects of rooftop garden on energy consumption of a commercial building in Singapore. Energy and Buildings 35: 353-364.   DOI   ScienceOn