Originally Posted by
ivor toolbox
So, open or closed, will make no difference to air coming in to cabin, but closed will reduce chance of a direct blast to the face.
Ttfn
I dont quite agree with that. The Punkah vents will be directing a flow normal directly at a person, whereas other flows will be more diffuse, reducing the airflow directly over a person, and also allowing contaminated vapour to land elsewhere.