In situ experimental determination of the heat transmittance of a building wall

Abstract

In this paper, results of a long term experimental in-situ measurement of air temperatures and heat fluxes trough a building wall surfaces, are presented. Indoor and outdoor measurements were carried out simultaneously during the period of 1 month in a dwelling of residential building located in Belgrade, Serbia. The data were used to calculate the thermal transmittance of the wall according Standard ISO 9869-1:2014. The U-value obtained from the experimental data and those calculated in steady-state temperature regime are compared. Criteria for the data that have to be met in order to get accurate U-value are discussed.