I use a 12x16 ordinary Nova (not FB) in a small darkroom and I have a mains voltage computer fan drawing air out at a top corner of the room, with fresh air coming in from a vent/light trap at the opposite bottom corner. The darkroom is in a larger shed and there is very little turbulence so there isn't much dust. I use a less smelly fixer (Kodak Flexicolor or other C41 fixer, pH less acid so less SO2) but a smellier stop bath (sodium metabisulphite) which smells of SO2. But because of the small surface area it isn't nearly as bad as open trays of rapid fixer and acetic acid stop bath.

The fan is only a 3inch model but it moves enough air to keep the room reasonably fresh.