Small hole or big hole?

An Architectural and Scientific Question: For example, I have a house/building which has a tube, one end of it is placed in the interior of the house, and the other on the outdoor. Regardless of other factors, such as its other design characteristics, location, temperature and pressure differences, etc., how should I design the tube if I want air to more likely go from the inside to the outside of the house through the tube? A. the interior end of the tube should have a smaller opening/cavity than the one on the outside; or B. the outside end of the tube should have a larger opening than the one on the inside.