Paper Conference

Proceedings of ASim Conference 2014: 2nd Asia conference of IBPSA-China, Japan, Korea


Energy Saving Effects of Green Roof in Existing Buildings with Low Insulation Levels

Hyeun Jun Moon, Kyeong A An, Seung-Won Han

Abstract: Energy performance evaluations of building envelope components, including external walls, floors, roofs, ceilings, windows, and doors, are important when determining energy requirements for heating and cooling, as well as energy saving potential. Green roofs are a viable option for reducing heat gain and loss in new and existing buildings. This paper evaluates the performance of green roof systems according to soil depth and Leaf Area Index (LAI), and attempts to quantify the effects on existing low-insulation buildings. Thermal performance of green roofs is mainly dependent on soil thickness and LAI. Installation of green roofs in existing buildings can lead to improvements in roof insulation, due to the soil layer. An increase in soil depth leads to a decrease in heating load, regardless of changes in the LAI. Larger LAI values lower the roof surface temperatures and reduce cooling loads in summer. A simulation study shows that the installation of green roof systems in existing buildings with low insulation levels, due to low thermal performance requirements when constructed, could improve the energy performance of the buildings. Installation of green roofs in old buildings could meet the requirements of the recent strict thermal performance regulations, thus, becoming a good green restoration option.
Keywords: Green Roof, Building Energy Performance, Leaf Area Index, Soil Depth, Roof Insulation level
Pages: 443 - 450