Thermography uses specially designed infrared video or still cameras
to make images (called thermograms) that show surface heat variations.
This technology has a number of applications. Thermograms of electrical
systems can detect abnormally hot electrical connections or components.
Thermograms of mechanical systems can detect the heat created by
excessive friction. Energy auditors use thermography as a tool to help
detect heat losses and air leakage in building envelopes.
Because wet insulation conducts heat faster than dry
insulation, thermographic scans of roofs can often detect roof leaks.
In addition to using thermography during an energy assessment, you
should have 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.