text: The phenomenon occurs when openings in an environment (including vehicles) or building (houses, factories, sheds, etc) are set on opposite or adjoining walls, which allow air to enter and exit, thus creating a current of air across the interior environment.  
  There is also a pressure difference between the opposite sides of the establishment. The effect is mostly driven by the wind, whereby the air is pulled into the building on the high pressure windward part and is pushed out on the low pressure downwind side of the establishment (because of the pressure difference between the openings). A winds effect on a structure creates regions that have positive pressure on the buildings upwind area and a negative pressure on the downwind side. Thus, the building shape and local wind patterns are critical in making wind pressures that force airflow through its openings.
  If the windows on both sides of the buildings are opened, the overpressure on the side facing the wind, and/or low pressure on the adjacent protected side, will make a current of air through the room from the uncovered side towards the sheltered side. If there are windows on both sides in a building, cross ventilation is appropriate where the width of the room is up to five times the floor-to-ceiling height. If openings are only one side then wind-driven ventilation is more suited for structures where the width is around 2.5 times the floor to ceiling height.