Osgeld:
more importantly you need to find something to actuate the vents that fit within the space requirements, the rest builds around that
Yeah, that's the part where I really have no idea where to begin. Most of the motors I've seen for sale seem to want much beefier power supplies than I can deal with, but I know toys exist with movement that run off a few AAs so there should be something available. Plus I'm not entirely sure of the best way to convert the motion of a motor to linear movement.