Performance Evaluation of Thermal Bridge Reduction Method for Balcony in Apartment Buildings

Xinwen Zhang,Kyu-Nam Rhee,Gun-Joo Jung

doi:10.3390/buildings12010063

Abstract

Most apartment buildings in South Korea use internal insulation systems to reduce building energy demand. However, thermal bridges such as balcony slabs in apartment buildings still lead to significant heat loss in winter, because the internal insulation system is not continuous in the balcony slab structure, and floor heating systems are commonly used in residential buildings. Therefore, this study investigates two types of thermal break elements, namely thermal break (TB) and thermal break-fiber glass reinforced polymer (TB-GFRP), to improve the thermal resistance of a balcony thermal bridge. To understand the effects of balcony thermal bridges with and without thermal break elements, the linear thermal transmittances of different balcony thermal bridges were analyzed using Physibel simulations. Then, the heating demand of a model apartment under varying thermal bridge conditions was evaluated using TRNSYS simulations. To understand the effect of insulation systems on heat loss through a balcony thermal bridge, apartments with internal and external insulation systems were studied. Whether the apartment was heating was also considered in the thermal transmittance analysis. Thus, the linear thermal transmittance of the thermal bridges with thermal break elements was reduced by more than 60%, and the heating energy demands were reduced by more than 8%.

Highlights

Persistent environmental problems, such as the lack of fossil fuels and global warming, are still major challenges for humans
The objective of this study is to analyze the effect of a balcony slab thermal bridge on the heating energy demand of apartment buildings
To evaluate the heat loss caused by the thermal bridge, the linear thermal transmittance of the balcony slab thermal bridge was analyzed first

Summary

Introduction

Persistent environmental problems, such as the lack of fossil fuels and global warming, are still major challenges for humans. Reducing energy consumption is necessary to improve environmental problems. Apartment buildings have less internal load compared to other buildings, they are envelope-load-dominated buildings. Heating load accounts for a large part of the total residential load, and more energy is consumed for heating. To reduce apartment building energy consumption, the performance of building equipment systems is improved, and innovative building components are used. A part of the heating load comes from the heat loss through thermal bridges of the building envelope, which in winter can be up to 30% of the total apartment building energy consumption [5,6]. Apartment buildings have a large potential for reducing energy consumption by improving the effects of thermal bridges. Increased attention is being paid to construction details where thermal bridges are present

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Discussion

Conclusion