Abstract: A building ventilation air inlet assembly for providing an adjustable venting assembly to permit automatic inlet of air includes a housing, an air opening extending through the housing, a valve plate pivotally coupled to the housing for selectively covering the air opening, an adjustable valve counterweight coupled to the valve plate for biasing the valve plate into a closed position, and a valve plate stop lanyard coupled between the valve plate and the housing for restricting opening of the valve plate. The valve plate stop lanyard includes a clip member for permitting adjustment of the effective length of the valve plate stop lanyard.