Thermal Image over shoulderOf all the tools that a home energy professional can bring to the inspection, few compare to the usefulness and “cool factor” of the thermal infrared camera. This powerful little tool allows the auditor to see what is otherwise invisible or hidden from view.

IR Cameras used to be outside the price range of most inspectors with cameras starting at around $5000, but recently, the technology has become less expensive and starter cameras can be had for around $1300. For the best resolution and features, most auditors still spend $5000 to $10,000 on a camera, so don’t be surprised if you are charged an extra fee to include thermography in your audit or inspection

Ducts on Ext WallsLeaky R0 hatchAs a home performance professional myself, I have used my thermal camera on nearly a thousand homes. Through these inspections, I have collected many interesting thermal images and would like to share them with you here. Hopefully these images will convince you to demand that your next home inspection or energy audit include the use of the thermal camera.

The best images come while running the blower door to depressurize the house and draw cold air through all the leaky spots. This is the best way to see what is otherwise invisible.IR_2563 The picture of this attic access hatch is the perfect example. Although the lid is insulated, since there is no rubber gasket or weatherstripping around the opening, air escapes around the edges. Under normal operating conditions, this would be air leaking OUT of the house and would not be visible. Only by putting the house under negative pressure with the blower door can we reverse the normal flow of air leakage and see pictures like this.

Here is a short checklist of things to remember when getting an infrared inspection:

  1. Since the camera only sees temperature differences on the surface, any interpretation of the images must be taken with a grain of salt until a complete visual inspection is made.
  2. Some cameras can provide great images with a minimal amount of temperature difference, but generally the best images can be seen when the temperature difference from inside to outside is greater than 20°. If the temperature range is close, you can push the difference a bit by turning the thermostat up or down in advance of your scheduled inspection.
  3. The images are somewhat grainy and difficult to identify later. Most cameras offer the ability to snap a regular digital picture and place it beside or behind the thermal image to help locate the area later. It may also be helpful to take some notes or mark the areas with a small piece of tape or a post-it note.
  4. IR Cameras are a powerful tool for identifying problem areas, however, they only provide images, not data. Don’t jump to any conclusions and start tearing open the walls based on a batch of pictures. While the camera can find many invisible flaws, it can also find flaws which are NOT cost effective or easy to fix.