Comparison of experimental and calculated thermal transmittance for timber‐framed outer wall constructions

Abstract

The importance of accurately determining the thermal transmittance factor for the outer walls of timber‐framed buildings is the driving force behind this research. This calculation is necessary for heating and cooling load determination, as well as energy consumption assessment. This research aims to conduct an analytical comparison, through both experimental and calculated means, of thermal conductivity coefficients of materials employed in the construction of buildings and structures. The methodological approach adopted in this research is grounded on an experimental analysis of the thermal transmittance of the outer wall materials in timber‐framed buildings. Thermal conductivity measurements with a Hot Plate apparatus by ISO 8302 and thermal conductivity calculations using mathematical software were the primary experimental methods deployed during the research. The results of this study demonstrate differences between experimental and calculated thermal transmittance values for timber‐framed outer walls. Moisture inconsistent distribution throughout the material is the reason behind these discrepancies, calling for particular humidity corrections in the calculations, varying across different materials. While working with simplified calculations of timber‐framed outer wall structures, monitoring the uneven heat flow in I‐beam joints is paramount and should be coupled with humidity‐related material changes. This study's practical implications are that the results can be implemented when calculating the energy consumption of building structures and the heating‐cooling load they entail.