A while back I posted a question about venting my cab (project Fargolet) to allow better operation of the cowl vent. The issue was that while the original cowl vent worked like a charm, it required cracking open a window to get the air to really flow well. The noise from the open window was horrendous, and it was right at ear level.
Here is the finished gizmo, which sits under the seat (seat bottom removed in the pic):
It's just a gate valve meant for RV use (dsraven’s idea) with the addition of a critter screen (leegreen’s idea). The gate valve is controlled by a push/pull knob at the base of the seat base. The results are fantastic! When I open the valve I get tons of air coming through the cowl vent to cool me off, with only a minute amount of noise as the air is now exiting the cab under the seat where it is nicely muffled.
Thanks for the ideas, guys!