Mobile QR Code QR CODE : Korean Journal of Air-Conditioning and Refrigeration Engineering
Korean Journal of Air-Conditioning and Refrigeration Engineering

Korean Journal of Air-Conditioning and Refrigeration Engineering

ISO Journal TitleKorean J. Air-Cond. Refrig. Eng.
  • Open Access, Monthly
Open Access Monthly
  • ISSN : 1229-6422 (Print)
  • ISSN : 2465-7611 (Online)
Title Analysis of Heat Flow Characteristics Through a South-facing Wall Directly Exposed to Solar Radiation and Convergence Condition for Thermal Transmittance Calculation
Authors Ji Yeon Byun ; So Min Park ; Ji Soo Shim ; Doo Sam Song
DOI https://doi.org/10.6110/KJACR.2023.35.3.126
Page pp.126-135
ISSN 1229-6422
Keywords 건물 외피; 수렴 조건; 남측 벽; 열관류율 Building envelope; Convergence condition; Southern wall; Thermal transmittance
Abstract The thermal transmittance of the building envelope greatly affects the heating and cooling load and is measured in accordance with ISO 9869-1. This method estimates the in situ U-value by measuring heat flux through the test wall and the temperature difference between the internal and external environments. Thermal transmittance can be calculated from data measured over five days under stable environmental conditions. However, if the environmental conditions are unstable, the minimum test period may be longer than 10 days to obtain reliable results. Therefore, in this method, the temperature difference between the inside and outside of the wall should be 10℃ or more, and the influence of solar radiation should be minimized. For a south-facing wall, the heat flux fluctuation is so large that it takes twice as long to be a convergence condition proposed by ISO 9869-1. This study aimed to analyze heat flow characteristics through a south-facing wall directly exposed to solar radiation and its convergence condition for thermal transmittance calculation.