ok, get 4 pc case fans, use two on both intake and outlet. hook them up on an old pc power supply (one with a mechanical switch not motherboard controlled, pick em up for a few cents) if you use these you can power your 12v grow chamber "furniture" quite safely and you can add shit. To help humid, get some of those Silica Gel bags you get in equipment or shoes things like that.
if you put a short length of pipe on the inside of your inlet and glue some "shelves" in it, lay the bags on the shelves so the air has to pass between them, slightly drying it.
It doesn't sound like it would make much of a change but it does that. also, try leaving one or two at the bottom of ya unit during flower, their not normally strong enough to like embalm ya plant overnight or anything but help airborne humid well.
Mor