This idea came out of one of my weird dreams, it kinda makes sense in the morning, I thought I'd run it by y'all and see what anyone else thinks.
It was a food dehydrator that worked by the chimney stack effect (heat rises and will pull cool air up behind it,
solar chimneys work that way) but in the house, with one
light bulb adding the heat to make the air rise and pull.
Trays of food stacked, open edges. The center core of the tray was cut out, and the central core had a light bulb at about 3/4 of the way up. The idea was the light bulb got the air moving upward from it's heat, and that pulled air across the trays.
Reading what I just wrote, I think it wouldn't dry anything heavy and wet as no heat is added to the air across the food, but would work for herbs and such.
Interesting. Wonder how this idea can be worked with, not as is, but the concept.