TY - JOUR
TI - Reliability of experimental methods to determine heat transmission coefficient of the existing building façade wall
AU - Peulić Slobodan
AU - Gajić Darija
AU - Mitrović Zoran
JN - Thermal Science
PY - 2025
VL - 29
IS - 3
SP - 2185
EP - 2197
PT - Article
AB - Experimental methods are often only possible solution to determining heat transmission coefficient (U-value) of elements in existing buildings. These methods can be of great importance in developing countries which are tackling energy poverty by conducting deep energy retrofit of the existing building stock, such as in case of Bosnia and Herzegovina. The ISO 9869-1 standard recognizes heat-flow-meter (HFM) methodology as enough precise to give reliable results. However, this methodology predicts strict criteria under which measuring can be done, what is sometimes not possible. Other method standardized with ISO 9869-2 includes quantitative infra-red thermography (QIRT) which is much suitable to conduct in-situ, yet, for its non-contact properties it is not as reliable as previous one. This paper aims to show process of implementation of these methods and statistically compare them to theoretical method made according to ISO 6946. Compared to theoretical heat transmission coefficient of Utheor.=1.366 W/m2K, results showed deviations ranging from S = –4.17% to S = +1.61% for HFM method, with mean value of Umean =1.39 W/m2K, and S = 5.38% for QIRT method, with mean value of Umean = 1.29 W/m2K. In this paper, a comparative overview is made to show importance and applicability of each method, their prerequisites and reliability in real context.