Ever hear that the difference between a boy and a man is the price of his toys. I thought my moisture meter at $400 was extravagant, but an IR Camera for $5,000 has now is a necessary home inspection tool.

An infrared thermal imaging camera produces an image of heat differences, as opposed to your digital camera, which takes a picture of visible light. IR technology for many years was a primary tool of police, military, science and space programs, but as the price has come down and the opportunity for training has increased, IR cameras are now frequent companions on home inspections. This technology is useful for home inspectors since it essentially permits the inspector to see what is occurring behind walls and other non-accessible areas. The camera measures temperature variances of surfaces to determine where heat, cold, moisture and even mold are in undesirable and inaccessible places.

The technology is based on a simple concept. Different materials retain temperatures dissimilarly. Thermal energy, or infrared, is light energy not visible to our eyes because its wavelengths are too long to be detected by the human eye. Every material with a temperature above absolute zero emits heat and therefore has an infrared radiation footprint. An IR camera is designed to show these patterns with hotter areas depicted as more yellow and red colors, and cooler areas shown as darker colors. This technology permits the IR camera operator to perform material inspections in a noninvasive manner.

For instance, water holds heat and gives it up more rapidly than solid materials, which are slower to heat and cool. This means that a wet area will have a different “temperature picture” on an IR camera image than a dry area. If this is occurring where air is leaking through a hot attic, the camera shows this vividly. Therefore, the IR camera has become a key diagnostic tool used by residential energy auditors. By depressurizing a home utilizing a blower door, Mother Nature demands that for every cubic foot of air ejected out of the home by the fan, one cubic foot of outside air be sucked into the home.

Invariably, the outside air temperature varies from the indoor air temperature, so the auditor can do a quick scan of the outside walls (called the “building envelop” to use more specific terminology) to find faults. With a little caulk and some additional insulation after the building is better sealed, money stops flying out all those failed areas. Energy audit protocols recommend a “test out” with the blower door to demonstrate the reduction in exterior air infiltration.

As a medical diagnostic tool, an IR camera is invaluable and eventually will be found in every doctor’s office. If you have a back problem, for instance, since our bodies attempt to make repairs by accumulating more fluids at pain sites, the temperature of areas of pain will be different (probably higher) that normal tissue. In color mode, an IR camera image will show the warmer temperatures brighter in the yellows and reds than the surrounding areas. This same principle applies to cancerous areas and other injuries. Diagnosing injury to a horse’s leg is being performed routinely with an IR camera for his reason.

Likewise, an IR camera study of a home during a home inspection adds one more diagnostic tool to ensure that the client gets a complete and thorough picture of the home. Also, an existing homeowner complaining of unusual odors or drafts in a home would benefit from an IR camera study. In the years to come, energy auditors will continue to rely on the infrared camera to be more confident that the energy audit shows the property in the proper “light.”

Note: This article was written by Arthur S. Lazerow, Certified RESNET Rater