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:
- 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.
- 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.