A novel methodology for the characterisation of airflow using infrared thermography and pressurisation test

Abstract

Although buildings have reduced energy consumption in recent years, high levels remain, primarily due to HVAC systems. Air infiltration, which significantly impacts thermal comfort and energy efficiency, is critical. Pressurisation tests are widely used to assess the airtightness of building envelopes, but they do not identify the specific locations or shapes of air leaks. In this context, combining thermography with pressurisation tools shows significant potential. Thermography enables the visualisation of temperature differences caused by air leaks, while pressurisation tests provide general information on a building’s permeability. This approach offers a more comprehensive understanding of building airtightness. However, the methodology currently only provides a general quantitative indication of permeability and locates some leaks. While promising, further research is required to enhance the precision and ability to quantify and address air leakage issues. This paper presents an experimental laboratory study to develop a methodology to characterise air infiltration. It uses a three-dimensional matrix placed near a controlled inlet, where cold air entering due to pressure differences alters the matrix’s surface temperature. These changes are detected by infrared thermography, enabling accurate airflow characterisation. This approach effectively identifies and characterises air leakage from a single IR thermal image for each airflow condition, providing valuable data for decision-making.