Reliability Field Test of the Air–Surface Temperature Ratio Method for In Situ Measurement of U-Values

Seo-Hoon Kim, Jong-Hun Kim, Hak-Geun Jeong and Kyoo-Dong Song
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Seo-Hoon Kim: Department of Architectural Engineering, Hanyang University, Seoul 04763, Korea
Jong-Hun Kim: Energy ICT·ESS Laboratory, Korea Institute of Energy Research, Daejeon 34101, Korea
Hak-Geun Jeong: Energy ICT·ESS Laboratory, Korea Institute of Energy Research, Daejeon 34101, Korea
Kyoo-Dong Song: Department of Architectural Engineering, Hanyang University, Seoul 04763, Korea

Energies, 2018, vol. 11, issue 4, 1-15

Abstract: This study proposes the air–surface temperature ratio (ASTR) method as an in situ measurement method to rapidly and accurately measure wall U-values in existing houses. Herein, the wall U-values were measured in situ applying the heat flow meter (HFM) method of ISO 9869-1 and the ASTR method. The results obtained using the HFM and ASTR methods were compared, and the relative error rate and accuracy of the measurements were analyzed. The aging rates of the wall U-values were compared and analyzed by comparing them with the wall U-values before and after the installation of retrofit insulation. Subsequently, the ASTR method was used to analyze the U-value measurement error rates according to the number of measurement days (one day to seven days). In addition, this method calculated the appropriate measurement period required to satisfy the measurement conditions. As a result, the mean relative measurement errors rates of the HFM and ASTR methods were ±3.21%. The short-term (one day) and long-term (seven days or longer) measurement results indicated the average error rates as approximately ±2.63%. These results were included in the tolerance range. Therefore, it was determined that the ASTR method can rapidly and accurately measure wall U-values.

Keywords: energy retrofitting of existing houses; U-value; heat transfer coefficient; quasi-steady state; in situ (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2018
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Citations: View citations in EconPapers (9)

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