Infrared thermography assessment of thermal bridges in building envelope: experimental validation in a test room setup

Thermal infrared imaging is a valuable tool to perform energy non-destructive qualitative tests and to investigate buildings envelope thermal behavior. The assessment of the envelope thermal insulation, ventilation, air leakages, and HVAC performance can be performed through the analysis of each thermogram showing the objects surface temperature. One of the crucial elements of the building that can be analyzed by thermography is the presence of thermal bridges that, together with windows and doors, constitute one of the weakest component in terms of thermal losses. A quantitative methodology was proposed in previous researches of the authors in order to evaluate the effect of these elements on the energy balance of the whole building. In the present work, in-field experimental measurements were carried out to evaluate the energy losses through the envelope of a test room setup. In-situ thermal transmittance measurements of the wall, ceiling and roof were continuously monitored and each element was characterized by its own thermal insulation value. Infrared thermography and the cited quantitative methodology were applied to assess the energy losses due to thermal bridges. The main results show that the proposed procedure confirms to be a robust tool to define quantitatively the incidence of thermal bridges in the envelope dispersions.