A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China

Abstract As the proportion of building energy consumption gradually increases, adding insulation materials to the existing building envelope has become an important method to improve building thermal performance. Currently, most research on the optimum thickness of insulation layers is calculated fr...

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Main Authors: Chengcheng Xu, Suola Shao, Wenjian Wei, Yanluan Qin, Nan Li
Format: Article
Language:English
Published: Nature Portfolio 2025-03-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-93945-y
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author Chengcheng Xu
Suola Shao
Wenjian Wei
Yanluan Qin
Nan Li
author_facet Chengcheng Xu
Suola Shao
Wenjian Wei
Yanluan Qin
Nan Li
author_sort Chengcheng Xu
collection DOAJ
description Abstract As the proportion of building energy consumption gradually increases, adding insulation materials to the existing building envelope has become an important method to improve building thermal performance. Currently, most research on the optimum thickness of insulation layers is calculated from the perspective of heat transfer. However, in humid and hot areas, the influence of humidity and solar radiation should not be ignored. Therefore, this study used the coupled heat and moisture transfer model to calculate the yearly cooling and heating transmission loads. Three kinds of materials: expanded polystyrene, polyurethane and extruded polystyrene were compared in thickness ranging from 10 to 90 mm. The P1-P2 economic model consisting of lifecycle energy P1 and lifecycle expenditure ratio P2 was used to calculate the optimum thickness, payback periods and energy savings. The results show that, the optimum thicknesses for expanded polystyrene, polyurethane, and extruded polystyrene are 66.8 to 74.5 mm, 38.3 to 40.2 mm, and 46.3 to 49.5 mm, respectively. The required payback periods are 5.57 to 5.72 years, 6.86 to 7.47 years, and 6.32 to 6.74 years, respectively. Expanded polystyrene is the most economical thermal insulation materials because of its lowest lifecycle total cost, the shortest payback period and the most energy savings. This study is helpful for obtaining more accurate optimum thickness of insulation layer in hot and humid areas, and guiding the renovation of existing buildings.
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issn 2045-2322
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spelling doaj-art-76c457901a7044cab41897ba8629dbb72025-08-20T02:49:34ZengNature PortfolioScientific Reports2045-23222025-03-0115111510.1038/s41598-025-93945-yA study on optimum insulation thickness of building walls in hot summer and warm winter zone in ChinaChengcheng Xu0Suola Shao1Wenjian Wei2Yanluan Qin3Nan Li4College of Civil Engineering and Architecture, Zhejiang University of Water Resources and Electric PowerSchool of Civil Engineering and Architecture, Zhejiang Sci-Tech UniversityCollege of Civil Engineering and Architecture, Zhejiang University of Water Resources and Electric PowerCollege of Civil Engineering and Architecture, Zhejiang University of Water Resources and Electric PowerCollege of Civil Engineering and Architecture, Zhejiang University of Water Resources and Electric PowerAbstract As the proportion of building energy consumption gradually increases, adding insulation materials to the existing building envelope has become an important method to improve building thermal performance. Currently, most research on the optimum thickness of insulation layers is calculated from the perspective of heat transfer. However, in humid and hot areas, the influence of humidity and solar radiation should not be ignored. Therefore, this study used the coupled heat and moisture transfer model to calculate the yearly cooling and heating transmission loads. Three kinds of materials: expanded polystyrene, polyurethane and extruded polystyrene were compared in thickness ranging from 10 to 90 mm. The P1-P2 economic model consisting of lifecycle energy P1 and lifecycle expenditure ratio P2 was used to calculate the optimum thickness, payback periods and energy savings. The results show that, the optimum thicknesses for expanded polystyrene, polyurethane, and extruded polystyrene are 66.8 to 74.5 mm, 38.3 to 40.2 mm, and 46.3 to 49.5 mm, respectively. The required payback periods are 5.57 to 5.72 years, 6.86 to 7.47 years, and 6.32 to 6.74 years, respectively. Expanded polystyrene is the most economical thermal insulation materials because of its lowest lifecycle total cost, the shortest payback period and the most energy savings. This study is helpful for obtaining more accurate optimum thickness of insulation layer in hot and humid areas, and guiding the renovation of existing buildings.https://doi.org/10.1038/s41598-025-93945-yOptimum thicknessCoupled heat and moisture transferP1-P2 modelPayback periodEnergy savings
spellingShingle Chengcheng Xu
Suola Shao
Wenjian Wei
Yanluan Qin
Nan Li
A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
Scientific Reports
Optimum thickness
Coupled heat and moisture transfer
P1-P2 model
Payback period
Energy savings
title A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
title_full A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
title_fullStr A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
title_full_unstemmed A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
title_short A study on optimum insulation thickness of building walls in hot summer and warm winter zone in China
title_sort study on optimum insulation thickness of building walls in hot summer and warm winter zone in china
topic Optimum thickness
Coupled heat and moisture transfer
P1-P2 model
Payback period
Energy savings
url https://doi.org/10.1038/s41598-025-93945-y
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