German to English Tech/Engineering Construction / Civil Engineering

This is a sub-title in a section regarding the field of application for a smoke ventilator. After this line, there is a table with values for slope (in degrees), smoke ventilator's nominal size and the value of Aw (aerodynamic thingummy) in m2.

I'm thinking of sthg on the lines of aerodynamic surface area but if you know a more precise and accurate way of phrasing this, please share ;-)