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2025 Vol.19, Issue 3 Preview Page

Research Article

Steady-State Energy and Exergy Analyses of an Electric Resistance Water Heater System

에너지 및 엑서지 접근법에 기반한 전기 온수기 시스템의 정상상태 분석

Habin Jo1
,
Masanori Shukuya3
,
Wonjun Choi2*
조 하빈1
,
슈쿠야 마사노리3
,
최 원준2*
1Doctoral Student, Department of Architecture and Civil Engineering, Chonnam National University, Gwangju, Korea
2Associate Professor, School of Architecture, Chonnam National University, Gwangju, Korea
3Professor Emeritus, Department of Restoration Ecology and Built Environment, Tokyo City University, Yokohama, Japan
1전남대학교 건축토목공학과 박사과정
2전남대학교 건축학부 부교수
3동경도시대학교 생태복원 및 건축환경학과 명예교수
*Corresponding Author
30 June 2025. pp. 126-138
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Abstract

As building insulation improves, the share of energy used by domestic hot water systems increases, elevating the importance of their efficiency. Conventional energy analysis, focusing solely on energy quantity, provides insufficient insight into system inefficiencies. Exergy analysis, which considers both the quantity and quality of energy, offers a more comprehensive understanding of thermodynamic performance. Despite their global prevalence, electric resistance water heaters have received limited attention in exergy research, which has predominantly addressed heat pump systems. To address this research gap, this study develops a steady-state exergy model for an electric resistance water heater and compares the outcomes of energy and exergy analyses to assess how the system utilizes energy from both quantitative and qualitative perspectives. The exergy analysis reveals that significant inefficiency arises from the conversion of high-quality electrical energy to low-quality thermal energy. Additionally, the water mixing process destroys approximately 22% of the final service hot water’s exergy. This research contributes to a better understanding of how the electric resistance water heater system operates in terms of both energy quantity and quality. It also supports the development of more efficient strategies for utilizing electrical energy in domestic hot water applications.

Keywords
Domestic hot water system
Electric resistance water heater
Exergy analysis
Water boiler
Energy quality
키워드
급탕 시스템
전기 온수기
엑서지 분석
온수 보일러
에너지 품질
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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 : 19
  • No :3
  • Pages :126-138
  • Received Date : 2025-05-02
  • Revised Date : 2025-06-02
  • Accepted Date : 2025-06-05
  • DOI :https://doi.org/10.22696/jkiaebs.20250011
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