Natural convection will do what you want. (If he removed the bookshelf,) air will get sucked in from the bottom, heat up, and then rise. The problem is that the warm air will sit under the ceiling. I think circulation would be better used to make sure the air doesn't stratify, ie blow some of the warm air under the ceiling downwards.

It's funny you should write this, because I've been meaning to try exactly this: I have a 12V cable lighting system running over the steam heat radiator in the room I'm sitting now, and I was going to put a 200mm computer fan across the cables blowing down. Power is already up there... ;-)