Infrared Thermography: See Your Building in a New Light
What Is Infrared Thermography?
A non-destructive diagnostic tool, infrared thermography detects thermal differences in building systems and components to uncover hidden problems, including:
- Roof deterioration caused by water penetration
- Leaks and moisture hidden under membranes and behind walls
- Heat and cooling loss caused by poor construction or wet or missing insulation
- Blockages and other malfunctions in HVAC and plumbing systems
- Overloaded electrical circuits, switches, and panels
- Construction defects and structural damage
An infrared survey gives a view of building conditions beyond what can be seen in a visual-only survey, and it enables investigative probes to be taken with greater accuracy.
How Does It Work?
The science behind infrared thermography is basic: Vibrating molecules in objects generate electromagnetic energy. At higher temperatures, molecules move faster and emit more energy. This energy—infrared radiation—isn’t visible to the human eye, but it can be detected with a camera equipped with an infrared sensor.
Thermal differences appear as different colors in infrared light. By analyzing the color distribution in infrared images, it is possible to pinpoint areas of a building that are warmer or cooler than other areas.
These thermal anomalies may indicate potential defects such as water infiltration, missing insulation, drafty windows and doors, or an inefficient boiler.
Baseline Infrared Survey
An infrared survey is a valuable tool for assessing the existing conditions of a building. The findings can then be used as a baseline for comparison with future surveys. A baseline infrared survey is particularly helpful to determine if a newly constructed property was properly constructed and if the systems were installed correctly and are operating efficiently. A baseline survey encompasses all of the major building systems, including facade, roof and roof-level components, HVAC, and electrical.
Infrared Leak Detection
Once water enters a building through the roof or facade it can travel far and wide, making it difficult to find the source and determine the extent of damage. Infrared thermography is effective at detecting water in hard-to-see areas, such as underneath the roofing membrane, behind walls, and inside shafts and conduits.
Thermal Roof Surveys
Deteriorated roofs and defective roof-level components, such as a ripped or blistering membrane, cracked parapets, missing flashing, etc. are major entry points for water, which can work its way deep below the surface of the roof. An infrared survey of the roof can locate areas of moisture that can cause leaks and structural damage to the underlying roof deck. Thermal surveys are especially useful for detecting wet roofing insulation.
For best results, an infrared survey of a roof should be taken under the right conditions. On a clear day, the sun heats the roofing surface and any water trapped underneath. At night the roof cools, but moisture under the membrane cools more slowly. (Water retains heat longer than solids.) Infrared images taken of the roof after sundown will show the thermal differences between the cooler areas on the roofing surface and the warmer ones where water is underneath the membrane.
Using the thermal map of the roof as a guide, investigative probes can be taken at the exact locations where water is indicated to determine the extent of deterioration. With this more thorough and detailed evaluation of the roof, the engineer or architect can prepare accurate design and specifications for a repair program before leaks and damage become worse.
Facades
In addition to the roof, facades are a critical component in keeping water out of a building. Defects in exterior walls, such as cracked or spalling brick, loose masonry, and deteriorated pointing, will allow water to penetrate the building, resulting in leaks and deterioration. In addition, a building that is not water tight also lets conditioner air escape, increasing a building’s energy costs.
A thermal survey of the building envelope can identify water penetration, missing insulation, drafty windows and doors, and faulty construction that leads to water and air infiltration.
Interiors
Thermal surveys taken from the inside of a building help pinpoint areas where water has settled behind walls, under floors, and above ceilings. Infrared thermography can also detect condensation that forms on behind-wall pipes that have not been properly insulated. Moisture build-up that goes undetected can cause mold and deterioration.
As water evaporates, it cools a surface. The areas of water penetration on the inside of the building, which are typically not exposed to the sun like the exterior, display as cooler than surrounding surfaces in infrared images. Using the thermal images to identify the areas of water penetration, the engineer or architect can track the sources of the leaks back to the envelope of the building. With a much more comprehensive view of the water infiltration, fewer investigative probes into interior walls are needed.
HVAC Systems
Infrared thermography is also used on boilers, chillers, burners, piping, duct work, steam traps, and other HVAC equipment to detect leaks, blockages, insufficient insulation, overheating elements, and other problems causing inefficient operations.
Because infrared thermography does not require contact with equipment or interfere with HVAC systems, there is no need to interrupt operations. Using thermal images, for example, the engineer can pinpoint blockages in piping without drilling or cutting open pipes.
Electrical Systems
When electrical systems become overloaded and malfunction, they can overheat, creating a serious hazard. Infrared images can detect electrical wiring, panels, circuit breakers, switches, and services boxes at higher temperatures than they should be, helping to prevent shorts, outages, and fires.