Home Energy Auditing with Thermographic Camera

When it comes to energy auditors, they will generally use thermography or IR scanning in order to detect air leakage and also air defects in building envelopes.

The way a thermographic inspection works

One thing you should know about thermography measures is that they use still cameras and IR video in order to measure surface temperatures. The tools are basically going to detect light from the heat spectrum and the images on the film or video will record that variations in temperature that exist throughout the house.

The colors in which these temperatures are going to be displayed in range from black for cooler areas and white for warmer areas. Based on the images he gets, the auditor will determine whether the homeowner needs to consider insulating his house or not. The images also act as a QC tool which tells the homeowner whether his insulation was properly installed or not.

One thing you should know about thermographic inspection is that they are either an exterior or an interior survey. Depending on the weather condition, the home inspector will take a decision on the best method he can use in order to inspect the house. Most of the times though home inspectors will do an interior scan and that is due to the fact that warm air that escapes from a building won’t always move in a straight line through the walls.

If there is any heat loss detected in one area of the exterior wall, then it may be caused by a flaw inside the wall. On top of that, detecting temperature differences on the property’s outside surface is a bit harder during windy weather. Because of that, in such cases, an interior survey is a lot more accurate since it benefits from a minimized air movement.

Concerning thermographic scans, they’re generally used while a blower door test runs. What the blower door does is that it increases the air leaking issue through the various defects in the building’s shell. As a result, the air leaks are going to appear as black streaks in the IR camera’s viewfinder.

Not only is it necessary to have your home scanned in order to assess its energy efficiency, but you should also consider it before you buy a new house. You may think that new houses are exempted from such problems, but the truth is that there are many of them which aren’t built properly and have severe air leakages.

Watch this very short video for an infrared camera in action and continue reading below the video clip.

Devices used for thermographic inspections

There are many kinds of devices that energy auditors will use in order to detect the energy efficiency of a property as following:

  1. Point radiometers are one of the simplest tools used during one such inspection. What this does is that it measures the radiation in one spot at a time and then shows the meter reading of a certain spot. In this case, the auditor is going to carefully pan the area with the device and then write down the various differences in temperature he finds.
  2. Thermal line scanners are also used for showing radiant temperatures that’s viewed along a line. This is a process which is going to show the various temperature changes along the line.

The IR imaging camera is currently one of the most effective devices for detecting a property’s energy efficiency and that’s because it produces a 2D thermal picture of the area and lets you see exactly where heat escapes from your house.

How to prepare for a thermographic inspection If you want to use such services, then you should first of all take the required steps that would allow the inspector to provide you with an accurate result. This includes removing drapes and also moving furniture away from the walls.

The most accurate thermographic images are going to be produced when there’s a great temperature difference between the exterior and interior air readings. In northern states for instance, thermographic scans are usually done in the winter. If you live in a southern state though, the scans will generally take place during good weather when the AC is on.

Keep in mind that in certain period of time year, you may be required to maintain a certain exterior/interior temperature difference for up to 4h before the inspector can perform the test.

Infrared Imaging Explained

If you’ve wondered what infrared imaging is all about, then you’re probably someone who loves physics a lot. Nevertheless, this is a method of capturing IR images not visible to the eye which are then going to be converted into images visible to the human eye. As humans, we can only see the visible light, but this is only a very small part of the electromagnetic spectrum. But what is this spectrum, you ask?

Well, it’s a special scale that classifies the various forms of electromagnetic radiation, such as radio waves, microwaves, infrared rays and so forth. So if you’d like to see in infrared light, then you’ll need to use infrared cameras and imagers since they feature special sensors which don’t operate by using visible light.

Any object or organism that has a temperature above absolute zero will be able to produce infrared radiation. However, when temperature increases, this also causes the molecular and atomic activity to increase which means that more thermal radiation or heat will be produced. This in turn is going to emit more infrared radiation.

Infrared radiation that is reflected from or emitted by warm objects can be easily picked up by long-wave thermal infrared imagers. This is because the imagers feature lenses that can have as much as 7000 sensors which can easily convert IR energy into electrical signals which are then going to finally be converted into a visible image.

What’s special about infrared light is its ability of penetrating areas which visible light could never be able to, allowing it to reveal obscure objects. As one can imagine, this makes it very useful in a lot of applications and it’s generally used by the military in order to produce gun sights, binoculars and other infrared imaging devices.

Firefighters, police and many other agencies can use these imagers to rescue individuals who are lost at sea, lost in the woods, to catch criminals and so forth. As a technician using infrared imagers, you can easily located under-heated or overheated parts in order to eliminate leaking chemicals that can lead to potential hazards.

Lastly, if you’re an archaeologist, you can use these imagers in order to monitor archaeological sites and examine artifacts, while if you’re a wildlife researcher, you can use them for studying warm-blooded animals in their natural habitats. There are currently many luxury cars, planes and ships that use infrared images, but they’re also used in astronomy telescopes and space satellites for research.

Infrared Imaging Bascis

Infrared Imaging, Infrared Thermography, and Thermal Imaging refer to a process of using thermographic cameras to produce images by detecting radiation in the infrared range of the electromagnetic spectrum. That range is roughly between 900-14000 nanometers.

And here is another way to put this: all types of objects emit infrared light / energy in a form of heat. Because each of the objects / its components as well as parts of our body have slightly different temperature an infrared camera sensor detects those temperature variations and “paints” an image based on those readings. Because the output image is based on radiation, dark or bright environment does not affect the image.