Air leakage occurs in a variety of different ways through all types of exterior walls. In cold or warm climates, air leakage is accompanied with moisture transport. This moisture transport when migrating through dew point temperatures, leads to moisture accumulation within wall assemblies. This moisture accumulation may result in premature deterioration and mould formation given appropriate prolonged environmental conditions. Commissioning of air barrier assemblies using infrared thermography is an effective means of locating areas of air leakage defects. Since the environmental conditions that commissioning or building condition inspections are carried out vary considerably, the resultant air leakage thermal patterns on wall surfaces vary accordingly. This paper will outline the various types of thermal patterns created by both positive and negative building pressures during exterior inspection of various types of masonry clad buildings. These thermal patterns can be extrapolated to similar naturally occurring air leakage thermal patterns created by wind, stack effect and lack of existing mechanical system pressurization. This paper will outline the variable thermal pattern conditions created by cavity wall construction in addition to homogeneous solid wall construction and face seal type assemblies.
To see the spark of a short circuit in an electrical component is a human ability. To detect the hot spot in a faulty electrical connection long before the component reaches a failure state is an ability which infrared thermography is noted for throughout the inspection community. Over the years, the inspection industry has developed various guidelines for different fault categories as it relates to measured surface temperatures. These temperature categories indicate the electrical connection's severity and in turn equate to a repair schedule. Typically during an electrical thermographic inspection the component's phase loading should be obtained by an electrician. However, quite often this is not achievable. In the absence of phase loading measurements, the thermographer must diagnose thermal patterns to accurately identify the fault type, i.e. loose, overload, etc.. More times than not, this predictive maintenance tool detects loose connections. Unfortunately, the phase connection's torque value is not obtainable during an infrared inspection to see how loose or tight the connection really is. Therefore, to measure the phase loading is only one aspect. Knowing the connections' torque value is another. This paper is intended to reveal the infrared relationship between variable phase loading, variable lug torque and the associated surface temperatures.