Building Envelope and Infrared Thermography

Infrared Thermography - How it Works in Building Science
By Alan Trauger


Infrared Thermography How It Works In Building Science

Thermography enables us to see and measure heat. All materials on earth emit heat energy, in the infrared portion of the spectrum. Unfortunately, the unaided human eye cannot see in the infrared. However, infrared cameras can not only see, but record infrared images and measure the temperatures of objects quite accurately.

Infrared thermography is the technique for producing an image of invisible (to our eyes) infrared light emitted by objects due to their thermal condition. The most typical type of IR camera resembles a typical camcorder and produces a live TV picture of heat radiation. More sophisticated cameras can actually measure the temperature of any or surface in the image and produce false color color images that make interpretation of thermal patterns easier. An image produced by an infrared camera is called a thermogram or sometimes a thermograph.

Objects are characterized by a variety of physical by a variety of physical parameters such as size, shape, and weight. The most frequently measured physical property is temperature. Heat is the byproduct of all work, whether it comes from electrical, mechanical, or chemical activity. Humans generate, contain, and transfer heat to run our industries and regulate our everyday environments. Unexpected temperature variations may indicate design flaws, poor workmanship, or damaged building components. Temperature variations can be used to recognize numerous anomalies.

Heat is an intangible thing. We cannot directly measure heat. We can only measure the effects of heat; namely by a temperature change. The amount of heat necessary to change the temperature of an object depends on the objects heat capacity. Thermography can pinpoint leaks in roofing and other building materials by exploiting the thermal properties of water. Water stores heat very well; it warms up or cools down more slowly than other materials common in buildings. This property is called "specific heat" by physicists.

Infrared Surveys are a quick and cost effective approach for assessing hidden water damage. Because the heat capacity of water damaged material is greater than that of dry material and air, areas of high moisture content appear warmer or colder than the surrounding infrastructure. Infrared scanning makes finding problem areas much easier. Combined with digital photography, it can greatly enhance the consumers understanding of just what the problem is and how to go about having it repaired. It also enhances the consumers ability to deal with the contractors that may be performing the repair work.

Infrared imaging allows us to evaluate the condition of the exterior cladding systems by mapping areas of moisture entrapment and the delamination due to environmental stress. Exterior cladding surveys are extremely cost effective, surveys are all non destructive. To a building owner or insurance company involved in property damage settlement, clear images of normally invisible damage can be invaluable for planning restoration efforts and rationalizing settlements.

Building envelope performance is vitally important for energy efficiency as well as occupants safety and comfort. An infrared scan may help detect or resolve hidden electrical, plumbing, insulation voids, storm drainage or structural problems, minimize risks and maintenance costs. Although infrared inspection does not directly detect mold, it is quite useful to find hidden moisture, where mold may develop.

How does Infrared fit into the Big Picture: It is a non destructive test that is able to detect problems before physical symptoms appear. Use to optimize building envelope performance to reduce energy costs. Increase building durability through timely minor repairs and reduces life cycle costs.

Alan Trauger is a Building Consultant that performs property condition assessments for residential and commercial properties. An experienced and knowledgeable problem solver, understanding processes and issues related to building structures and their systems. An expert witness, trainer, and educator. To view past newsletters on construction and buildings http://newsletters.alantrauger.com/ To review authors bio, qualifications, and interest in receiving future email newsletters http://www.alantrauger.com