Do not fan it. You are oxidizing it and the resulting oxide is liquid drops that you see.
Instead, tilt the tray on the one side when you place it into the freezer, then after the precipitation, tilt the tray to other side so the solvent will not cover the crystals and leave it like that for another 8 hours or so, then just pour off the solvent, cover the tray with plastic wrapper, make few small holes in it and put back into freezer to dry.
Also, could be water condensing on the sub-zero surface. Just leave it to dry in the freezer.
Vac chamber is a good idea as well, though i would use hexane instead of heptane/naptha. Easier to purge in vacuum
Gate Gate Pāragate Pārasaṃgate Bodhi Svāhā