I have the option of piping an outside air intake to my woodstove either directly through the floor below (run length to get below 2x10" joists w/ fiberglass batt insulation, cabin is ~4' off the ground) or through the wall it is sitting next to (run length of ~2' inside and through 2"x6" w/ fiberglass batt insulation). Both runs would essentially be straight.
But is there a distinct advantage to one route vs. the other--going through a wall vs. directly below to the floor. Going through the floor is straight forward and would be a straight run... but would require more work (cutting tile/cement board/etc.). Going through the wall would be a slightly longer run (part of which would come from having to use a couple 90* bends), but would be easier. So is there a engineering advantage (lets put the work required to install aside)?