Hey AFN
I'm looking to buy a new fan prefer oscillating clip on. Right now I have an air king lol it's far from living up to its name. I bought it for 50$ plus tax at a grow shop and am not impressed with it at all. It's for a grow tent that is 3x3 wide and 6.1 feet tall.
I've just up grade one of my cheap clip on 6" fans for slightly more expensive one (not much), its called the monkey fan by secret jardin, its only 13w and a hell of lot quieter than my other 2, it feels like they designed it for grow tents. Its doesn't oscillate but air movement has quieten a lot. I'm now going to up grade all of mine to them, bring the noise down and save a few watts.