Thermal Imaging is used for a variety of purposes. The basic process is using a camera capable of seeing IR(Infra Red) spectrum of light. In the simplest example above, I’ve used a handheld Thermal camera capable of 60 x 60 thermal pixel resolution, and it provide a slightly higher visual resolution so you see a bit more detail of the object. Also shown is the centre point temperature, listed on top of the image, and the max and min temps shown on the bottom left corresponding to the 2 other targets that float around the image finding the extremes. There’s also the emissivity coefficients setting, but that’s getting overly complicated. This particular camera doesn’t lock the thermal image colours to specific temperatures, but simply fades between them to help identify colder and warmer spots. This is the Feature that we will focus on for home energy loss identification. You can also see the colour spectrum this camera uses on the bottom right, for coldest to warmest (left to right). Using the thermal image of this BBQ Barrel, I can quickly identify it’s hot and cold spots, and some actual temps of specific spots by using the centre crosshairs, and it looks like 190.1 degrees C on the lid means its ready for the burgers. 😎
Above we have a visual image of a back door next to a window on its left, and the max temp appears on the right side of the door above the light switches, and the min temp appears to be in the window on the left. When we view the Thermal image on the right, we can clearly see the temp ranges of the window and bottom of the door are similar colour and therefore similar temperature. We can also see other cold spots near the doorknob and in the corner, left of the door. Upon closer physical inspection we find quite a draft at the bottom of this door, plus poor seals on the sides. It might be worth noting that trying this test in the heat of the summer would work best if this home was also air conditioned, but it’s not, so the winter is the best time for this testing. The Hot spot (max:71.2F) above the light switch is caused by the switch being an electronic dimmer, and it actually generates a bit of its own heat. This door needed some serious attention to cut down these potentially costly leaks of energy.
Now let’s take a look at a more complicated scenario, the image doesn’t appear to show any significant hot or cold spots to focus on. This is actually a great image of a well insulated front door. What is very telling is that both the hottest and coldest spots are both up along the ceiling/wall junction. And we also see a warm spot at the light switch location, as this switch is actually a smart switch with lcd display, it generates some heat. I like the fact that we don’t see any lines, between the colours, around the majourity of the door frame. Upon physical inspection of the door, we discovered good seals all around the door, and no drafts.
Using a thermal imager for energy loss detection is one of the many valuable tools available. Since thermal cameras are so much cheaper than they used to be, easily available for as little a few hundred $, some might think about getting their own. If you happen to be a handy person, you can rent a high quality Thermal camera for very little and do some of your own investigation for leaks of heat/cold loss. If you want a quality review of your potential energy losses, then you will want to engage an Energy Auditor with experience, to help find the most cost effective areas of focus. Thermal imaging is only one of many tools an experienced Auditor uses. They will pay for themselves quite easily.