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2026 Vol.46, Issue 3 Preview Page
Thermal Performance and Surface Condensation Resistance by Design Factors Considering Thermal Bridge in Double-Window System with Insulating Glass Units of Apartment Buildings

공동주택 복층유리 이중창의 열교 부위를 고려한 설계 요소별 단열 및 결로방지 성능 개선 효과

JaeRim Kim1
,
Jiwon Bae2
,
Jaehan Lim3*
김 재림1
,
배 지원2
,
임 재한3*
1Undergraduate Student, Department of Architectural and Urban Systems Engineering, Ewha Womans University
2M.S. Student, Department of Architectural and Urban Systems Engineering, Ewha Womans University
3Professor, Department of Architectural and Urban Systems Engineering, Ewha Womans University
1이화여자대학교 건축도시시스템공학과, 학부생
2이화여자대학교 건축도시시스템공학과, 석사과정생
3이화여자대학교 건축도시시스템공학과, 교수
*Corresponding Author
30 June 2026. pp. 135-147
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Abstract

Double-glazed windows with polyvinyl chloride (PVC) frames, which are widely used in residential buildings in South Korea, exhibit low thermal transmittance because of the material properties of PVC. However, metal reinforcements are typically inserted within the frames to ensure structural stability. Owing to their high thermal conductivity, these metal reinforcements can act as thermal bridges within the frame, thereby providing preferential heat transfer paths through the window assembly and increasing the system’s overall thermal transmittance (U-value). In addition, the structural deformation of the frame or microgaps at the joints can induce air leakage, resulting in additional heat loss owing to infiltration. To mitigate these effects, air-sealing materials are commonly used to improve the airtightness of window-frame joints. In this study, the thermal performance of double-glazed PVC windows in residential buildings was quantitatively evaluated by considering the heat transfer characteristics of thermal bridge regions. Particularly, the effects of structural reinforcements and air-sealing materials on thermal performance were analyzed. Numerical simulations were conducted to investigate variations in the thermal transmittance of the window system based on the type of glazing unit, material and configuration of internal reinforcements, and the presence of air-sealing materials. The simulation results indicated that the use of low-E glazing and insulated reinforcements resulted in significant improvements in the thermal performance. In addition, the application of air-sealing materials contributes to the reduction in heat loss.

Keywords
Double-glazed windows
U-value
Heat transfer analysis
Thermal bridge
키워드
복층유리 이중창
열관류율
전열 해석
열교
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Information
  • Publisher :Korean Solar Energy Society
  • Publisher(Ko) :한국태양에너지학회
  • Journal Title :Journal of the Korean Solar Energy Society
  • Journal Title(Ko) :한국태양에너지학회 논문집
  • Volume : 46
  • No :3
  • Pages :135-147
  • Received Date : 2026-03-31
  • Revised Date : 2026-05-05
  • Accepted Date : 2026-05-13
  • DOI :https://doi.org/10.7836/kses.2026.46.3.135
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