A:Answer I have not done a dehydrating yet. For me, I always want to be safe. Example, if I'm using the "air fryer" and not everything could fit in one rack, then I would put the rest on the bottom rack. If you are able to put everything in one rack, you should really put aside the other rack(s) out, if you are not using it, because it can get really hot inside, just to be on the safe side.