Performance of Thermal Break Strips in Lightweight Steel Framed Walls

An accurate thermal characterization of the envelope components is essential to achieve a reliable evaluation of thermal behaviour and energy efficiency of buildings. In lightweight steel-framed (LSF) building components, the major thermal performance concern is related to the unwanted significant thermal bridge effects originated by the high thermal conductivity of steel. The application of thermal break (TB) strips in the steel stud flanges is one of the most currently used thermal bridge mitigation strategies. In this paper the thermal performance of ten interior LSF walls configurations are measured, using the heat flow meter (HFM) method under laboratory-controlled conditions. Three TB strips materials and three TB locations (inner, outer and both sides of steel stud) are assessed and a comparison with the thermal performance of a reference wall without TB strips is made. Regarding the TB strips materials, it was found that the best thermal performance is achieved by aerogel, which is the material that presents the lowest thermal conductivity. Considering the TB strips location, the application on both sides of steel stud shows a relative significant thermal performance increase comparatively to the application on inner or outer side, presenting these last two configurations very similar performances.