Try and follow me on this: I have 2 1K watt HID lights in 6" air cooled hoods. I have an AC unit, one of those that has a vent out for a window but not be IN the window deals that vents out 6" duct. I have the lights together and they cool just fine with some fans I got at menards that suck but run. I want to upgrade and control this funky smell cuz it's going down the block! My best thought is put the choarcoal filter as the start to line that goes filter to fan to light to light to out. but I have this ac duct too and its exhaust can smell....... this is where I start going in circles. ideas? Thanks in advance.