Vacuum drying, like vapor degreasing, dries equally on outer and inner parts’ surfaces. Our systems vacuum dry until a low enough monitored pressure level is reached to assure that all solvent has been removed from the part and the chamber.
For very light pars that tend to cool very rapidly during vacuum drying, a heated recycled air stream can get applied to the chamber to assure complete drying.
In no case is external air or other non-condensable gas used for drying. All the drying gas is recycled in a closed loop so that there is no solvent leaving the system.