By "vertical" do you mean that the air is being directed towards the top of the case?
If that is true, then the ideal path for the air would be to continue in a straight line out from the second U9B fan and drawn out the top of the case with the assistance of a case fan mounted in that location.
Any additional fans would ideally be situated on the bottom of the case to draw cool air in the bottom, having it pass vertically through the case, the CPU and out the top.
Most users have air move horizontally in the case; cool air drawn in the front and the warm air exhausted out the back.
But the vertical option is perfectly acceptable too.