Measurement and Analysis of In-situ Thermal Resistance and Thermal Transmittance of Apartment House Opaque Exterior Wall during Winter Season by Application of Thermal Storage Effect

2017 ◽  
Vol 24 (6) ◽  
pp. 802-809
Author(s):  
Myeong-Jin Ko ◽  
Doo-Sung Choi
Keyword(s):  
Thermal Resistance ◽  
Winter Season ◽  
Thermal Storage ◽  
Storage Effect ◽  
Exterior Wall ◽  
Apartment House ◽  
Thermal Transmittance ◽  
Measurement And Analysis

scholarly journals Analysis of Convergence Characteristics of Average Method Regulated by ISO 9869-1 for Evaluating In Situ Thermal Resistance and Thermal Transmittance of Opaque Exterior Walls

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1989 ◽  
Author(s):  
Doo Sung Choi ◽  
Myeong Jin Ko
Keyword(s):  
Thermal Resistance ◽  
Average Method ◽  
Test Duration ◽  
Test Environment ◽  
Building Envelopes ◽  
Thermal Transmittance ◽  
The Third ◽  
U Value ◽  
R Value

In the last few decades, an average method which is regulated by ISO 9869-1 has been used to evaluate the in situ thermal transmittance (U-value) and thermal resistance (R-value) of building envelopes obtained from onsite measurements and to verify the validity of newly proposed methods. Nevertheless, only a few studies have investigated the test duration required to obtain reliable results using this method and the convergence characteristics of the results. This study aims to evaluate the convergence characteristics of the in situ values analyzed using the average method. The criteria for determining convergence (i.e., end of the test) using the average method are very strict, mainly because of the third condition, which compares the deviation of two values derived from the first and last periods of the same duration. To shorten the test duration, environmental variables should be kept constant throughout the test or an appropriate period should be selected. The convergence of the in situ U-value and R-value is affected more by the length of the test duration than by the temperature difference if the test environment meets literature-recommended conditions. Furthermore, there is no difference between the use of the U-value and R-value in determining the end of the test.

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