I built my own down draft spray booth using a Jenn-Air range exhaust fan that I removed when I remodeled my kitchen. It's very quiet and powerful. I can rattle can or air brush enamels 8 feet away from my wife in our hobby room and she doesn't smell the paint. Therefore I'm always able to spray at room temperature. But as has been pointed out in prior posts, these things are nothing more than an exhaust fan, so they are always going to pull air out of the room and along with that, dust and hair. Running the fan for a while first, a quick spray, and then covering with a plastic tub seems to do a lot to mitigate dust, but I still get it sometimes. Sand and re-shoot, it's a pain but I think it's inevitable that it's going to happen sometimes.