Pretty neat, how about having the dryer tubing go up and down, that should be less turns than side to side I think. Could probably even just change that one, it'd take the same amount of tube.
I need to figure a way to have less bends in the ducting to increase air flow. This will increase heat transfer and lower radiant heat loss out of the face of the panel.
I would consider placing the ducting long ways rather than from side to side, that way you would minimize the bends. Just an idea...