When conditions are right, it is possible to
  locate missing or damaged insulation, such
  as this poorly installed injected foam in a
  residential building.

 

 
  The improperly installed fiberglass yields
  an irregular thermal pattern. The
  resulting cold spots commonly host wall
  stains or mold growth.

 

 

 

  Many types of insulation are susceptible
  to air infiltration. The fiberglass shown
  here does not stop air flow through the
  wall section.

 

 

 

 
   All the framing and insulation is clearly
   visible in this commercial building. Normal
   pressure differences on the top floor
   result in air leaking past the envelope
   through various pathways.

 

  Hydronic heating coils embedded in a
  concrete floor show up in this thermal
  image.

 

 

  This black wall is not uniformly grouted
  as was specified, leading to severe
  structural problems. Image courtesy Phil
  McMullen.

 

  The wet insulation in the roof system
  shows up clearly due to its greater
  thermal capacitance.

 

 

  The quality of the images produced by
  modern IR systems is remarkable. Missing
  and poorly installed insulation is easily
  seen.

 

 

  Another view, under different conditions,
  of the same house shows how results
  can vary as circumstances change.

 

 

 

  Air wash along the edges of batt insulation
  produces a unique cold signature on the
  ceiling of this wood-frame commercial
  building.

 

 

   
  The relative thermal performance of
  three windows  ̶  single-glazed (top),
  double-glazed with nitrogen gas (right)
  and double-glazed with argon-fill (left), is
  readily apparent in this thermogram taken
  from inside during the heating season.

 

 

 
  A typical insulated glass unit showing edge-
  effect losses and a more pronounced pattern
  at the bottom due to internal convection.

 

 

 

 

 

 

  Condensation formed first on the right window
  which was exhibiting a more advanced stage of
  argon gas loss than the left window. The
  thermograph shows that in fact both windows have
  the same argon loss.

photos courtesy of Snell Infrared