As the price of energy rises, architects, engineers, and especially building owners are becoming increasingly aware of energy consumption. Once a building is fully constructed, it may be difficult to pinpoint causes of energy leaks or inefficiency. Oversights in construction such as failing to properly insulate a space or not flashing an opening correctly can lead to some of these losses. Since very few owners are willing to disassemble their buildings in search of these deficiencies, a non-intrusive method for identifying energy leaks may be useful. Thermal imaging is a relatively new development in the world of energy analysis and testing and can be used to identify some of these energy inefficiencies or defective construction details.
A thermal imaging camera creates an image that represents the surface temperature of objects. Technically speaking, the technology is known as “FLIR” which stands for Forward-Looking InfraRed which means that it is looking for infrared heat (which is not visible to the eye). It is the same technology that you see on police shows when a helicopter is searching in the dark for someone and they show up as a giant white (hot) spot against the cooler (black) of their surroundings in the video. Applying this idea to buildings allows an engineer to “see through” building components to some extent and find areas of heat which are abnormal. Just like the police chase videos, most energy studies using thermal imaging are conducted at night or in dark areas so that solar heating and reflections do not throw off the results or provide false information. This is important because something as simple as a physical color difference in materials can provide a very different image to the camera during the daytime since lighter material will appear cooler whereas darker areas of the same material will appear hotter. At night, color differences don’t affect the image, giving engineers a much more accurate representation of the internal properties of the construction.
The image below provides an example of how thermal imaging can assist in identifying insulation deficiencies. In this case, all of the houses except the “yellow” one lack cavity wall insulation. As a result, they are losing large amounts of heat to the exterior environment. Additionally, all of the houses shown have poor roof insulation.
Thermal imaging has many additional applications as well including identifying air and water infiltration, tracing ductwork, or finding hot spots on electrical panels (to name a few). Engineers can be trained and licensed to interpret the results of thermal images ensuring that correct methods are used to obtain the images and then to make responsible decisions based on their findings.