Comparing U-Value Measurement of Building Envelope Using Infrared Thermography and Heat Flux Meter Method

The building stock and the construction industry together represent the most energy-consuming sector in the world. Indeed, existing building retrofit is a real challenge. The energy needs estimation of these buildings requires particular attention to the thermophysical proprieties of the envelope composition. The majority of efforts have been focused on analyzing the energy needs of existing buildings and their actual energy consumption measurement using dynamic thermal simulation and only some studies have evaluated in situ the thermal performance of the existing building envelope. Therefore, this study explores the potential of non-destructive methods, such as the heat fluxmeter method and infrared thermography, to assess the difference in expected and measured building Heat transfer coefficient (U-value), particularly for buildings with low U-values. Consequently, this paper discusses the potential of non-destructive approaches, including heat-fluxmeter methods and quantified thermography, to evaluate all differences arising from predicted and measured buildings heat transfer coefficient (U), particularly those with low values. Following the procedure described in this article, the value of the fluxmeter method could be approximated between 33.92 and 3.36% of the design U-value, compared to about 30% for quantitative infrared thermography. The obtained results will then help the experts to select the best method according to ambient conditions, implementation of the method and specific data analysis.