Well 'circulating' the air inside the case is one of the weirdest idea I've heard. Usually the way you're supposed to do it is, get the air in, have it pass over your components or areas of heat, and exhaust out. You shouldn't have mini-hot tornados inside the case.
If you have a specific area that's running hotter than normal, and the current airflow doesn't really flow over that heat generating area, then you might want to consider rearanging the airflow if you can, or use one of those spot coolers to cool the area off and get the hot air out to another part of the case where it can be exhausted out.