I wouldn't rely on them to drop the temp any more than 1-2 degrees. They mainly reduce ambient heat from the reflectors, so the more lights you use the better they work.
I am running 4x 1,000w lights in a 14x9 room.
Each pair of 2 lights is aircooled, with an 8" inline fan on both sides (one pushing air one pulling air).
So with that said, can i expect a drop in temps? or is it a waste of money?
i am only guessing they will drop a couple of degrees. whatever heat is coming off the top and sides of the hood will be insulated with those covers so it will help.
since your going to cover 4 lights, then you may get more than 2 degrees. imagine getting 2 degrees lower per light!
whats the temps in the room and the temp of the intake air to the room?
Well as far as FLIR paranoia goes, i would imagine they would still see the heat coming out of the bottom of the light lol... not to mention the room itself. However, my room right now is in the mid-high 70s. i just installed the covers and im doing a test run so ill keep everyone posted on the results.