Infrared Thermography Diagnostics of Air Permeability Through Building Openings – Assessment of its Reliability

The presented paper deals with an analysis of the reliability of a diagnostic method of air permeability through building openings (windows, doors, glass walls) by the application of infrared thermography. A test sample of a plastic double casement window was experimentally tested for air permeability and watertightness in a large pressure chamber. Different levels of the tightness were adjusted between the casement and frame part of the window. Additionally, the window test sample was measured in the large climate chamber with variant air pressure differences. Moreover, the surface temperatures were measured on the window by thermocouples and subsequently compared with images directly taken by infrared thermography. The effect of the increased air infiltration can be detected by infrared thermography but cannot quantify the overall air permeability of the window. The distribution of the exterior window surface temperature is influenced by several factors which should be taken into consideration in the final assessment of the window.