This drawing illustrates the wind conditions required to accomodate a common misconception among roofers (and promoted by a ridge vent manufacturer) regarding the supposed " short circuit " of an attic ventilation system.
For a "short circuit " between ridge vent and gable vent to occur, the wind flowing past a house must only act on, or flow over, the ridge vent at the peak of the house. The low pressure created at the ridge of the house would then draw air from any other opening/vent in the attic space.
Obviously, the wind does not act in the manner shown.
Wednesday, 15 February 2012