What is Thermal Imaging?
Thermal imaging measures radiated infrared energy and then converts the data to corresponding maps of temperatures, referred to as thermographs. Thermographs provide temperature data at each image pixel (over 17,000 detectors) and typically, cursors can be positioned to each point with the corresponding temperature on the screen.
How does it work?
Thermography measures surface temperatures by using an infrared camera, which sees light that is in the heat spectrum. Images on the camera record the temperature variations of the building's skin, ranging from white for warm regions to black for cooler areas. The amount of radiation emitted by an object increases with temperature, therefore thermography allows one to see variations in temperature.
The images below show heat loss though a garage entry door and around the sill plate/box frame - the areas that appear in red and white in the thermographic image.
What are the uses for thermal scans?
Thermography can be used to detect a variety of issues during a professional Home Energy Audit, including:
Heat loss and air leakage in the building envelope - Which can be a major source of energy loss.
Missing, damaged or wet insulation - Thermal imaging can be used to detect missing or displaced insulation with ease and accuracy, resulting in lower utility bills and added comfort within the home. In addition, because wet insulation conducts heat faster than dry insulation, thermographic scans of roofs can often detect roof leaks.
Moisture intrusion - Moisture issues are often concealed, sometimes deliberately, in an attempt to cover up moisture intrusion. A thermal scan can quickly, accurately and non-destructively locate thermal patterns that can be associated with moisture intrusion.
Thermographic scans are also commonly used with a blower door test running. The blower door helps exaggerate air leaking through defects in the building shell. These air leaks appear as black streaks in the infrared camera's viewfinder.
In addition to using thermography during a Home Energy Audit, you should consider having a scan done before purchasing a house; even new houses can have defects in their thermal envelopes. You may wish to include a clause in the contract requiring a thermographic scan of the house. A thermographic scan performed by a certified technician is usually accurate enough to use as documentation in court proceedings.
Other Thermal Imaging Uses
Find blockages in visible drain pipes
Locate animals nesting in the attic or wall cavities
Locate moisture intrusion in low or flat roof systems
Locate cold air infiltration around windows, doors and penetrations
Find leaks or lines in Radiant flooring systems.