Thermal-based analysis for the automatic detection and characterization of thermal bridges in buildings

Abstract

There are several techniques for the performance of energy studies in buildings, where infrared thermography is widely used for the study of the composition of the envelopes, to find faults in the building materials and in the composition of the envelopes with influence on their thermal behaviour, as well as to detect areas with humidity. Common thermographic building interpretations are performed by a human operator, which involves a high level of subjectivity and mainly relies on the expertise of the operator. With the aim at minimizing this subjectivity and maximizing the accuracy of the inspections, this paper presents a procedure for the automation of thermographic building inspections mainly focused on thermal bridges. The procedure, in addition to detecting the thermal bridges by their geometric characteristics and their temperature differences with the surroundings, includes the computation of the thermophysical property of linear thermal transmittance of each candidate to thermal bridge, thus implying their characterization in addition to their detection. With this addition, together with a previous process of rectification of the thermal images analysed, the accuracy of the detection of thermal bridges regarding existing methodologies is improved in 15% considering the false positives and negatives obtained in each methodology.