Three-dimensional characterization of air infiltration using infrared thermography

The energy consumption in buildings is still very high despite its reduction in recent years. Buildings' conditioning is the main cause of this energy consumption and, in this sense, air infiltration has a great impact. The control of air infiltration is essential to achieve thermal comfort and energy efficiency. The evaluation of the global airtightness of the building envelope based on pressurization tests has been broadly used to determine the airtightness of buildings, but it cannot define the shape of air leakages. The use of thermography in combination with pressurization tools could be very useful. This paper presents the laboratory experimental measurements to obtain a three-dimensional definition of the air temperature when passing through a controlled envelope gap. The method is based on the bidimensional temperature matrix, captured by infrared (IR) thermography, that the air leakeage produces close to the gap, and depending on the configuration of the air inlet and airflow. The temperature measurement was done using a non-continuous rendering surface in order to avoid the Coanda effect that opaque surfaces cause, achieving in this way a 42% increase in the measuring accuracy. (C) 2020 Elsevier B.V. All rights reserved.