Residential Energy Auditors uses infrared scanning to detect thermal defects and air leakage in building envelopes (homes walls and ceilings).
How does it Work: Infrared measures surface temperatures by using still cameras. This tool sees light that is in the heat spectrum. Images that are captured record the temperature variations of the building's skin. The results of these images help the auditor determines where air leaks are entering the home. They also serve as a quality control tool, to ensure that insulation has been installed correctly.
We decide which method would give the best results under certain weather conditions. Interior warm air escaping from a building does not always move through the walls in a straight line. Heat loss detected in one area of the outside wall might originate at some other location on the inside of the wall.
Infrared scans are also a common tool used with a blower door test running. The blower door helps exaggerate air leaking through defects in the building shell.
Infrared scanning allows us to check the effectiveness of insulation in a building's construction. The resulting infrared scan help auditors determine whether a building needs insulation and where in the building it should go.
In addition to using infrared scans during an energy audit, you should have a scan done before purchasing a house; even new houses can have defects in their thermal envelopes.
Pictures below show areas of concern from an infrared scan completed during an energy audit in the summertime. Notice the yellow area in which some heat is moving through the drywall in picture one and two. In picture three, the infrared camera shows areas of no insulation.