ISO 9869-1 평균법과 동적법에 따른 현장 열관류율 측정의 일치성 및 재현성 평가 = Evaluation of the Consistency and Reproducibility of In-situ Thermal Transmittance Measurements Using the Average and Dynamic Methods According to ISO 9869-1

국문 초록 (Abstract)

이 연구는 ISO 9869-1의 평균법(AM)과 동적법(DM)을 비교하여 건물 외벽의 현장 열관류율(U-value) 측정 신뢰성을 평가하였다. 북향 단열벽체를 대상으로 7개월간 측정을 수행하고, 실내·외 온도차 15~30 °C 조건별로 두 방법의 정확도와 재현성을 비교하였다. 분석 결과, 두 방법은 전 온도 범위에서 높은 상관성을 보였으며, 동적법은 평균법 대비 약 15.9 % 낮은 변동성을 보여 재현성이 우수하였다. 이는 비정상상태에서도 동적법이 보다 안정적이며, 재현성과 일관성이 측정 신뢰성의 핵심 지표임을 시사한다.

다국어 초록 (Multilingual Abstract)

This study aims to evaluate the reliability of in-situ thermal transmittance (U-value) measurements for building exterior walls by comparingthe Average Method (AM) and the Dynamic Method (DM) specified in ISO 9869-1. Unlike previous studies that assessed accuracy relativeto the theoretical U-values calculated by ISO 6946, this research focuses on reproducibility and agreement between methods under varyingenvironmental conditions. Field measurements were conducted on a north-facing insulated wall specimen over seven months, and analysiscases were classified by indoor–outdoor temperature differences of 15 °C, 20 °C, 25 °C, and 30 °C. For each case, U-values were estimatedusing both methods, and accuracy, reproducibility, and consistency were quantitatively compared. The results showed that the two methodsexhibited strong correlation, with nearly identical accuracy across all temperature ranges. However, the Dynamic Method demonstrated superiorreproducibility, reducing variation by approximately 15.9 % compared to the Average Method. These findings indicate that while bothmethods yield reliable U-values, the Dynamic Method is more robust under non-steady-state conditions. The study suggests that reproducibilityand consistency provide more practical indicators of measurement reliability than theoretical accuracy alone.