Building thermal bridge heat losses quantification by infrared thermography. Steady-state evaluation and uncertainty calculation

This study deals with the measurement of thermal bridges properties in building walls. The methodology is tested on an experimental wall built in laboratory. The setup thermal bridges transmission coefficients ψ and χ are measured in steady-state by infrared thermography. To do so, the thermal bridges impact factor I_tb is calculated. In the proposed method, the value of the surface emissivity is not required: only apparent temperatures are used. Experiments proved good reproducibility. Calculations of the uncertainties enabled to identify infrared measurements as the main sources of error.