| Keywords |
Opaque exterior wall ; Thermal transmittance ; Thermal resistance ; Progressive average method ; Average method considering the storage effect |
| Abstract |
This study evaluates the possibility of shortening measurement time to obtain the accurate in situ thermal transmittance (U-value) and thermal resistance (R-value) by the average method considering the thermal storage effect (AMSE) compared to the progressive average method (PAM). The measurement campaign was conducted on the opaque external wall of an apartment house located in Seoul for two weeks in the winter and was performed in compliance with the ISO 9869-1 standard. As a results of the measurement, U-value and R-value analyzed by PAM did not converge during the two weeks period, even though the experimental conditions specified in ISO 9869-1 were met. The analytical results by AMSE show that as the correction period to apply the storage effect becomes longer, the fluctuation of Uvalue and R-value greatly decrease and two values tend to converge to the respective asymptotical values. Therefore, although extensive research is needed for more cases, it is considered that AMSE can shorten the measurement period to determine the U-value and R-value to a reasonable level of accuracy. |