If you’re not a pro, what should you mind when using a thermal camera on your own?
Just using this image as an example. This was taken around 3pm in winter at a single family home in Chicago. That day was warm, so there wasn’t a big temp difference between inside and outside.
One thing I learned that thermal camera only shows surface temperature. It doesn’t tell you what’s happening inside the wall or inside the window frame. The window materials had been sitting in direct sunlight for hours, so they absorbed a lot of heat. What you’re seeing here is mostly stored surface heat, not insulation problem.
If there isn’t much temp difference between inside and outside, the image can be misleading. What looks like an insulation problem might be the sun heating things up.
If you're checking for air leaks around doors and windows, it’s better to scan when there’s a clear temperature difference and no direct sunlight. Early morning, late evening, or a cloudy day usually gives more reliable results. That way you’re not fighting solar heat interference.
Another thing beginners overlook is emissivity. Different materials on windows and frames reflect heat differently. Metal, painted wood, glass...they don’t read the same. If you don’t adjust emissivity, the numbers can be off by quite a bit.
The main point is that thermal cameras are great for spotting patterns and temperature differences, but it’s easy to misread the image data. You need the right conditions, and you have to understand what you’re looking at.