my smooth brained take is that 1 looks more efficient, especially if you’re looking for a more directable heat flow; 2 looks like it’d be solid if your goal was just to heat the area the miners held in
Discussion
The area the miner is held in and the area above are separate. The decision here lies in either routing excess miner heat through (1) a pipe that moves into the upper area for ambient heat flow and then ports out the top, or (2) route the heat solely through the lower area with a low intake and high outtake, with the component area above being heated by ambient heat through small holes.