I am somewhat familiar with the shaker hood. In that situation, air enters the intake with a ram effect, which increases with increasing speed. The shaker is a closed system. The lower plate has a rain baffle that keeps driven rain from soaking the front of the filter. Puddling water on the lower plate is drained off through rubber tubes that dump to the ground below. The filter element is actually elevated slightly higher than this rain "gutter" in the lower plate.
