Influence of Temperature and Moisture Content on Thermal Performance of Green Roof Media

Bohan Shao, Caterina Valeo, Phalguni Mukhopadhyaya and Jianxun He
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Bohan Shao: Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
Caterina Valeo: Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
Phalguni Mukhopadhyaya: Civil Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
Jianxun He: Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada

Energies, 2021, vol. 14, issue 9, 1-21

Abstract: The influence of moisture content on substrate thermal conductivity at different temperatures was investigated for four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 and −10 °C, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature. Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature’s amplitude for the green roof with 150 mm thick substrate. When a sedum mat was added, there was a 20% reduction in the amplitude of the inner temperature as compared with the cell without a sedum mat.

Keywords: green roof; thermal conductivity; moisture content; heat flow meter; thermal performance; frozen soils (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

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