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Research Article

A Preliminary Study on Heating Load Savings through Enhanced Insulation in Unheated North-Facing Common Spaces of Apartments

아파트 북측 비난방 공용공간의 단열 보강과 난방부하 절감 효과에 대한 기초 연구

Hyun-Jae Chang1*
장 현재1*
1Professor, School of Architectural Engineering, Hongik University, Sejong, Korea
1홍익대학교 건축공학부 교수
*Corresponding Author
28 February 2026. pp. 84-94
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Abstract

In Seoul, South Korea (37.6°N), north-facing building envelopes receive no direct solar radiation during winter and are exposed only to diffuse solar radiation. In typical Korean apartment buildings, which predominantly adopt reinforced concrete wall-bearing systems, heat transfer through north-side concrete walls is expected to be affected not only by indoor–outdoor temperature differences but also by the substantial thermal mass of concrete. This study investigated the winter heat transfer behavior of unheated north-facing common spaces in a flat-type apartment building, focusing on heat flux and surface temperature responses of envelope components. The influence of concrete thermal capacity was examined, and the potential heating load reduction achieved through insulation reinforcement was evaluated. The results showed that the external wall accounted for the largest heat loss among the components of the common space. Heat flux through the external wall exhibited a time lag of approximately 4 h in response to outdoor temperature variations. In the common space wall, heat loss occurred at the inner surface while heat gain was observed at the outer surface during periods when outdoor air temperature exceeded the core air temperature. This indicates that heat transfer was governed not only by instantaneous temperature differences but also by time-delay and attenuation effects of temperature variation associated with concrete thermal mass. Insulation reinforcement of 30 mm applied to the core wall reduced the heating load by 2.4%. Extending the insulation to the kitchen-side balcony increased the reduction to 3.9%, while including the north-facing pipe shaft further enhanced the predicted reduction to 6.1%.

Keywords
공용공간
열용량
열유속
단열보강
키워드
Common spaces
Heat capacity
Heat flux
Insulation reinforcement
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Information
  • Publisher :Korean Institute of Architectural Sustainable Environment and Building Systems
  • Publisher(Ko) :한국건축친환경설비학회
  • Journal Title :Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
  • Journal Title(Ko) :한국건축친환경설비학회논문집
  • Volume : 20
  • No :1
  • Pages :84-94
  • Received Date : 2025-12-31
  • Revised Date : 2026-02-19
  • Accepted Date : 2026-02-19
  • DOI :https://doi.org/10.22696/jkiaebs.20260008
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