I have an 13 m x 13 m opening in a tower wall which starts at 10 m above the ground level, (so the top of the opening is 23 m above the ground). This opening is 90 degrees or perpendicular to the predominant direction of the wind, which has a basic velocidade of 33 m per second. The opening in the tower wall can not be closed and so I am trying to size a ventilation system to pull air so that no (zero) dust escapes.

First of all: What is the calculation to convert 33 m/s into kgf/cm2?
Second: How do I calculate the vacuum effect of the wind passing the tower/doorway in order to overcome this effect?