FLIR is very sensitive to changes in head, however it supposedly is very easy to fool with proper insulation, good sealing, and finally running lights during the day when your house is hot anyway... Think about it on average in Florida your attic is going to be running anywhere from 90 - 140 degrees depending on your insulation, roof ventilation, and a few other factors like tree cover over the roof.
Running lights at night will make the room hotter, but not necessarily the attic or roof top. If you're concerned about it you could try this
"Make your own FLIR" I don't guarantee that this will be as sensitive as cop FLIR systems but it should give you a decent idea of if you're leaking light or heat out of your room.
Also watch this vid,
"FLIR bust" the video clearly shows that the windows are the weak point in their op. Would they have gotten busted had they properly sealed their windows? I personally would have caulked a 'black board' behind some cheap blinds to prevent light from escaping, then put the highest rated insulation I could find (R30 is GREAT, if you can afford to have someone 'butter' with R30+ foam even better) in the remaining window frame, put up a 'fake wall' over the entire existing wall, completely seal it with joint compound, and finally then wrap the whol thing in the thickest reflective material I could find (I hear panda film is excellent for defeating FLIR.) As a 'double check' you could double wrap the room with a dual sided material like panda film with white facing out and black in and then white in black out.
Also you could use FLIR to your advantage. If you don't have an existing grow op call a home inspection company and ask them to do a FLIR diagnostic of your house. They will be able to go through and tell you where insulation is failing, not installed, or incorrectly installed. Having them 'pre tour' your grow room might save you some leakage of IR before you even set up. Fix the problems in the house construction and then address over doing it.
Just some thoughts. I have read, but not verified for myself, that Florida considers FLIR an invasion of privacy and it is no longer a valid 'reason' to get a search warrant. I haven't verified this yet but it's been mentioned several times on this board.
-RT76
