So we all have heard about Block-IR, and how it is suppose to block your thermal signature from FLIR. Well all Block-IR is is a attic radiant barrier. It reflects thermal radiation, which FLIR picks up. Here is a test showing how a radiant barrier is effective. [ame=http://www.youtube.com/watch?v=jsbLHDNg1iU&feature=related]Radiant Barrier versus Fiberglass Insulation Hot Box Test - YouTube[/ame] That is the same exact thing as Block-IR. Now think how it would look on a thermal FLIR. The left side with the radiant barrier would look normal, and the right side would look overly hot. Here is a thermal image of a painted radiant barrier in an attic on the inside, sure not the exact same as Block-IR, but effectively the same thing. They left one spot uncovered, look at the difference! And that thermal heat is from the sun, alot more powerful then a few grow lamps. I also have access to a thermal camera which I will be getting in about 2-3 weeks, and I will be taking before and after images of my grow room to confirm that Block-IR is effective.