I have often been asked whether to blow air into the bin, or suck it out. The short answer is to blow it in. There are several reasons to blow: First we will utilize the heat given off by the motor to aid in the drying process. If we suck, that heat is just wasted. Also when we blow, there is compression of the air that occurs, which manifests itself in the form of heat. We have measured this compression to be 5 or 6 inches of water (supports a column of water in a manometer) and this results in an increase temperature of a couple of degrees. This also helps in the drying process. And the third reason is somewhat more practical. Blowing will keep all the little holes in the screen open, whereas sucking will plug the holes with fines.