On a recent thermal examination of a house I was called on to find the usual - diagnose why rooms are hot and cold, if recent roof repairs stopped further moisture intrusion as intended, and so forth. It went well.
I had a very unusual diagnosis to make also. My client said, "When I am standing at my kitchen sink, I can smell what is going on outdoors. For example, when my neighbor fertilizes his yard, I can smell it almost immediately."
There are many things a thermal image camera can detect, but I have never used it to diagnose fertilizer smells.
But why not try? So I set out to find the problem. Air infiltration was happening somewhere. But where?
Looking above the kitchen sink it wasn't hard to see why.
The sink is located in a 3 foot bump out, with its own double window. That's a pretty common architectural design. But looking above we see why air, and smells, can get in. The left image is of the window and the ceiling above the sink. The right image is the corner of that bump out, over the corner cabinet. The cannister lights and square light over the sink are evident.
The purple area is the ceiling of that bump out. There is no insulation there! That area is 58 degrees F. The outdoor temperature is 55F. There are soffit vents under the gutter just over that window, where air is supposed to get in. It does!
What is in that air will easily filter into the kitchen, through those lights and even through the drywall! Hence, the fertilizer smell.
She said, "Oh, so that's why it gets so hot and cold there when I am at the sink!" Um, yes!
My recommendation: Don't underestimate the power of your home inspector's thermal infrared camera! We inspectors are finding new uses for them every day!