Infrared (IR) Thermography (also known as an infrared thermal scan) is a useful tool to help find anomalies that may otherwise remain hidden in walls, floors and ceilings. Infrared energy is heat energy. Since all objects on Earth are above absolute zero (-273° C), they emit heat energy to varying degrees, even ice cubes! A properly trained infrared thermographer can interpret an infrared image and determine if a roof or plumbing leak exists, if there is missing wall or ceiling insulation, if an electrical component is reaching critical temperature levels, or if no major issues exist at all. The purpose of most thermography work, as performed by home inspectors, relates to looking for anomalies within a building. An anomaly is a situation that is otherwise not to be expected under normal conditions.
Matthew Steger, inspector/owner of WIN Home Inspection has been trained and certified by the Infrared Training Center (ITC) to perform Infrared Thermography. Examples with photos of just some of the issues that we have found by using infrared technology are shown below under "Some Infrared Thermography Applications".
Heat is energy and is continually moving to an object or surface with less heat. Once two nearby objects are at the exact same temperature, there will be no further heat transfer between these two objects. Also, there is no such thing as 'cold'. Cold is just a relative term meaning a lower amount of heat energy compared to a warmer object. For infrared technology to work properly, objects must be at different temperatures. If you were to walk into a room where everything was the same temperature, IR technology wouldn't be of much use since the infrared camera would see most (or all) of the objects at near the same temperature. Luckily, in homes and other buildings there are various components such as walls, ceilings, plumbing, electrical wiring, heating/cooling equipment, and insulation. Each of these systems and components relate with heat energy in some way and how well these systems deal with heat energy is where infrared technology comes in.
Moisture within a building can damage building components and can lead to rot and/or mold. Quick moisture detection is key to minimizing potential damage and repair costs. An infrared thermography camera can see the heat transfer characteristics common with moisture and helps show what is wet or damp and what is dry.
How does Infrared Thermography work?
Thermography is defined as obtaining and analyzing thermal information using a non-contact thermal imaging device. An infrared camera does not measure temperature. Instead, it measures heat energy. Infrared technology doesn't see through walls and isn't X-ray vision nor is it night vision, but instead allows the user to examine the heat transfer characteristics of the objects around us. Thermal imaging can work in complete visual darkness since the visual light spectrum (what we can see with our eyes) and infrared spectrum are at different wavelengths (approx. 0.4 to 0.75 micrometers for visual energy vs. 1 to 1000 micrometers for infrared energy). The type of infrared thermography cameras that most thermographers use measure IR energy in the 8~12 micrometer "long-wave" wavelength range.
Using an infrared camera, warmer objects are typically lighter in color (red, orange, yellow, or white). Cooler objects are typically darker in color (blue, purple, or black). To an untrained eye, a bunch of odd patterns, shapes, and colors on the infrared camera's screen can easily be confusing or totally misdiagnosed. Issues such as cold air entry may look similar to missing insulation or the issue may be completed missed. To the properly trained infrared thermographer, however, these anomolies can be properly identified. When the infrared camera indicates evidence of a potential leak, for example, the issue should be confirmed with a moisture meter assuming the area in question is safely and physically accessible.
If properly done, a thermal image can also be "thermally tuned" to highlight the issue(s) of concern within the image and to maximize thermal contrast in the image or to 'filter' out heat transfer above or below a set temperature.
How is an Infrared Thermography Scan performed?
An infrared thermography scan entails going room to room in the building and analyzing the walls, floors, ceilings, heating/cooling registers, etc. of each area. The first thing that needs to be done is that the building to be scanned needs to be prepared well prior to the scan beginning. Furniture, book cases, and wall coverings (mirrors, paintings, etc.) should ideally be removed away from the walls. For a thermal scan to work properly, the bare walls should be visible to the camera as much as possible. A painting on a wall or a sofa or bookcase against the wall prevents the wall from being seen both visually and using the infrared camera. Also, heating or cooling equipment should be running at least 4 hours (12 hours is even better) before the scan is performed to help allow for a good temperature difference between interior and exterior.
By thermally conditioning the building prior to the scan, a good temperature difference (at least 12 degs F, but 18 degs F is even better) should exist between the building's interior and exterior. Remember, as noted above, for heat to transfer, there needs to be a difference in temperature between objects. This should provide ideal conditions to find heat transfer, and, as you know, infrared thermography is all about heat transfer. If a building's interior temperature is nearly the same as the exterior temperature, little heat transfer will occur, and there will be little to be seen using the IR camera.
The hotter and cooler that two nearby objects are, the faster heat energy will transfer from the hotter to the cooler object. Also, certain materials have a higher thermal capacitance. Thermal capacitance is a measurement of how well an object or material retains heat. Water has a higher thermal capacitance than air. This is why water holds warmth longer than nearby air does. Understanding thermal capacitance is yet another example of why it is critical that a professional infrared thermographer be properly trained.
Some Infrared Thermography Applications:
The above photos show missing insulation at ceilings, walls, and at a wall/cathedral ceiling junction.
Missing insulation is shown above at an attic access panel ('scuttle'). This wastes energy and lowers interior comfort in the home. From our experience, the attic access location in most homes is rarely properly insulated.
This infrared image shows in-floor radiant hot water heat. The image confirms the heat's operation plus knowing the exact location of these pipes is critical before drilling through the floor.
Just last week, I inspected a Cape Cod home and found a roof leak alongside a dormer that would have totally been missed without performing an IR scan.
There were no stains on the dining room ceiling providing any indication of a leak. The first photo below shows what the ceiling looked like (no stains
visible). The 2nd photo shows an overlay of the IR image (showing the water from the roof leak) over the original photo. A moisture reading of the area
confirmed an active leak. The home buyer was very happy that he elected to have me perform the IR scan in addition to his home inspection.
The above IR image illustrates the heat energy given off of by energized wiring (infrared vs. visual). This is a normal occurrence when wiring is energized (powered). A properly trained infrared thermographer will be able to decipher what is considered normal versus what may be considered excessive heating of wiring.
Some other IR applications (not performed by this company) entail:
Learn more about Infrared Thermography here.
Matthew Steger, owner/inspector of WIN Home Inspection, is an ASHI Certified Inspector (ACI) and a Certified Level 1 Infrared Thermographer). He can be reached at: (717) 361-9467 or email@example.com.
The contents of this webpage were authored by Matthew Steger, ACI - owner of WIN Home Inspection in Elizabethtown, PA. No website content may be reproduced or copied without prior written consent of Matthew Steger.
WIN Home Inspection provides home inspection services in Lancaster, Elizabethtown, Ephrata, Mount Joy, Denver, Lititz, New Holland, Hershey, Gap, Reinholds, Landisville, Columbia, Annville, Lebanon, Cleona, Manheim, Willow Street and surrounding areas.