Analysis of the Applicability of Non-Destructive Techniques to Determine In Situ Thermal Transmittance in Passive House Façades

Abstract

Within the European framework, the passive house has become an essential constructive solution in terms of building efficiency and CO2 reduction. However, the main approaches have been focused on post-occupancy surveys, measurements of actual energy consumption, life-cycle analyses in dynamic conditions, using simulation, and the estimation of the thermal comfort. Few studies have assessed the in situ performance of the building fabric of passive houses. Hence, this paper explores the applicability of non-destructive techniques—heat flux meter (HFM) and quantitative infrared thermography (QIRT)—for assessing the gap between the predicted and actual thermal transmittance of passive house façades under steady-state conditions in the Mediterranean climate. Firstly, the suitability of in situ non-destructive techniques was checked in an experimental mock-up, and, subsequently, a detached house was tested in the real built environment. The findings revealed that both Non-Destructive Testing (NDT) techniques allow for the quantification of the gap between the design and the actual façades U-value of a new passive house before its operational stage. QIRT was faster than the HFM technique, although the latter was more accurate. The results will help practitioners to choose the most appropriate method based on environmental conditions, execution of the method, and data analysis.

Analyzing Thermal Images to Evaluate Thermal Protection in Residential Structures: Lessons from Russian Practices

“…Using an overview thermogram of the external surfaces of enclosing structures, areas with compromised thermal insulation properties are identified, subsequently subjected to detailed thermography from the internal side of enclosing structures [3][4][5][6][7][8][9][10]. Thermography can be either overview or detailed [5][6][7][8][9][10][11][12][13][14][15]. Overview thermography involves thermal imaging of external and/or internal surfaces of enclosing structures.…”

Correction of Temperature from Infrared Cameras for More Precise As-Is 3D Thermal Models of Buildings

“…This method is limited to walls with a low thermal mass, and measurement campaigns span several days, during which only night-time measurements are used for calculation. However, some authors state that a reliable value of the U-value can be extracted in short measurement times [28].…”

Non-Destructive Testing in Civil Engineering

“…Article [8] examines the use of a heat flux meter and quantitative infrared thermography to assess the difference between the predicted and real thermal conductivity of house facades under steady-state conditions in the Mediterranean basin. First, the suitability of NDT techniques was tested experimentally, and then a single-family house was verified in a real environment.…”