The waxed (smooth) side is stamped for the inspector, faces in -- on roofs and rooms, so he can see the rating at inspection. Used in an attic, OSB would practically stop the moisture coming through from below and possibly mildew or mold on the face. Or, you may be alright. Carpet and pad is not a good idea unless the room is heated, not ventilated attic.
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!