It has been sometime since this was addressed in previous threads. I tried an AC powered 15W clip on 6" fan attached to ceiling of tent, air flow was quite poor, I would need several of these. I want a fan or two with decent air flow, low wattage. I saw previous posts years ago about the 18v lithium battery powered Ryobi or Ridgid brand fans, are they still the way to go? They now have 20V fans from similar brands like Dewalt, Kobalt at Lowe's. I already have several Dewalt 18v batteries for my drill so I wonder if these will work in the 20v units? Ryobi even has a misting fan you put over a bucket of water, but then would that possibly affect the art if there is too much moisture? I was going to connect the fans to my marine battery set up I have yet to get for my lights, but wattage would be too great, requiring more or heavier batteries I suppose. Any comments?