Inspecting buildings with today’s imaging systems seems so easy. However, many thermographers are discovering the hard way that is not! If you know the basics, you should be able to get good results most of the year—but without that foundation of knowledge, you’ll never even know what you missed.
To be successful, you must understand how buildings are constructed and how they work. In the United States and Canada, most residential buildings are constructed using a wooden frame with insulation installed continuously over the “building envelope,” as it is called. But insulation alone is not enough because it typically does not control excessive air movement through the envelope. Think of how you feel when the wind blows through your clothing—not too ideal, right? With that example, you can appreciate how your house is affected.
Several important industry standards exist to guide thermographers who are inspecting buildings, most notably:
• ASTM C-1060 Thermographic Inspection of insulation Installations in Envelope Cavities of Frame Buildings
• ISO 6781 Thermal insulation, qualitative detection of thermal irregularities in building envelopes, Infrared Method
• ASTM E1186 Air Leakage Site Detection in Building Envelopes and Air Barrier Systems
• Canadian National Master Specification: Thermographic Inspection Services of Building Envelope
Any of these copyrighted standards are available from various online sites and can be downloaded for a small fee.
In addition to these, an important new standard is about to be published by RESNET, the organization that has taken the lead for government supported residential efficiency programs in the United States. This details not only how an inspection is to be conducted under the Energy Star and Home Star programs, but also speaks to the certification process that will be required of thermographers doing the inspection. Of course, other building inspection standards can be found in other parts of the world and these may inform the activities of thermographers in those areas. If you are using thermal imaging for buildings, it is important to become familiar with any of the standards relevant to your situation.
John Snell—The Snell Group, a Fluke Thermal Imaging Blog content partner