Despite what you might have seen on television or in movies, thermographic imaging cameras can't see behind walls. Instead, they detect temperature variations related to heat and moisture along building surfaces.
Anything with a temperature above absolute zero emits heat. A thermal camera is able to detect this heat and create a thermal image based on that information. A qualified professional then examines the thermal image and assesses what's potentially going on behind the surface that’s causing the temperature variations in the thermal image.
Thermographic imaging cameras can detect serious problems the naked eye can’t see, such as:
air duct leaks
inadequate or non-existent insulation
heating and cooling losses
abnormal heat from an appliance or electrical system
If these problems go undetected they can cause extensive damage to your home.
The only way to detect insulation problems without tearing down your walls is by using a thermographic imaging camera.
A qualified inspector can detect if there is adequate insulation in your walls and attic space by using a thermal camera. During warmer months of the year the inspector is looking for warm spots in the thermal image whereas in the winter they're looking for cool spots.
The image on the right is a picture of a ceiling inside a home. Everything seems to fine. But a thermal image reveals heat penetration due to insufficient insulation.
Because the thermal image was taken in the summer the interior surface should be cooler than outside. This is indicated by the darker purple areas. But the yellow/orange area at the apex of the ceiling indicates that heat is penetrating through, which tells a qualified inspector there’s a problem with the insulation in that area.
A thermographic imaging camera can identify electrical problems by looking for abnormal heat emanating from an electrical system.
The picture on the right is of an electrical panel. Scrolling over it reveals a thermal image that shows significant temperature variations. The yellow/orange areas indicate heat is accumulating in the panel and wiring, which could be due to overloaded circuits or other electrical problems.
Thermal imaging is also used to detect moisture before it penetrates through interior walls and surfaces. Trapped moisture leads to mold, so the earlier it's caught the better.
The picture on the right of a home’s interior shows nothing out of the ordinary. But the purple areas in the thermal image reveal that there are cool spots along the wall and ceiling. The general shape of the temperature variations captured in the image indicates moisture.