[Although this appears under my byline, the following is a guest post from John Snell. John is the founder and a partner in The Snell Group and works as an Instructor, Consultant and Director of Curriculum. In 1994 John had the honor of becoming one of the first thermographers in the world to obtain a Level III Thermal/Infrared certificate from ASNT. John knows IR! And at GreenHomes, we agree the infrared thermography is an important diagnostic tool and a standard part of every audit.]
John Snell using an infrared camera
Many homeowners are having high-quality energy audits conducted by trained professionals. Honestly, it is the only way to ensure work will be done properly and yield effective results. More and more auditors are now using infrared thermography as part of that process. It only makes sense as thermography can both speed up an audit and make it much more effective. In the end, this extra bit of work makes lots of sense for everyone involved in making a home more energy efficient.
Infrared images can help locate and identify thermal defects in a home.
What should you know about infrared? First, it is not magic! We cannot see through walls and much of what we learn is based upon a greater understanding of the building. Typically we can find the framing and any existing insulation. This should make any bids for insulation work more accurate and lower in cost because they are based on reality. When used in conduction with a blower door, always recommended, we can also find sites of air leakage. Again, this will make the air sealing work much more cost-effective.
Second, the thermographer needs to not only be formally trained but also have the kind of qualifying experience that will make s/he the expert you want involved in your project. Thermography looks simple! It is not “rocket science” but it does require basic training and experience to become an expert.
The dark areas in this imagine show problems areas in several stud cavities that warrant further investigation
Imaging systems are electronic “cameras” that are sensitive to seeing heat that radiates from all surfaces. An insulated wall will look different than an uninsulated one as will the framing and any air leakage. The thermal image is usually quite easy to “read” especially with the help of a knowledgeable auditor; the images, either in color or gray scales, can delivered to you electronically or in a printed form. Not all imagers on the market will yield good results in buildings so, if you have any doubt about the end results, ask the auditor if their system meets the minimum standards required by RESNET.
A “test out” infrared inspection may also be done after the work is in place to provide assurance the work has been done to high quality standards. Even with the best of crews this is an important piece of “insurance” for everyone involved. If you are the building owner, it may also be useful to you to obtain or purchase copies of the inspection report so that that information can follow the building through its life cycle.
I’ve looked at thousands of buildings since I first used this remarkable technology in 1983. While standards suggest an 18F inside to outside temperature difference is required to locate insulation issues, the truth is with modern imagers and a skilled thermographer, we can often work with less of a difference and we can now work nearly all year long. When the auditor schedules the inspection, they may pump up the heat, close windows, open up interior doors or turn down the AC (if you have it), all to get better imaging conditions. The auditor will also need full access to all of the inside and outside of your home. The whole inspection will only add about 30-60 minutes to the audit and, in the long run, you’ll see significant savings of time as a result.
An investment in a thermography inspection will yield quite a return! In fact, I cannot imaging auditing a building without an imager (and blower door). It just doesn’t make sense.
The Snell Group