Span-Tech® creates a jet stream that will always give you favorable weather. Work inside of a Span-Tech® filled with livestock and the air quality is very acceptable -- summer or winter. Why? A jet stream is created by air flowing in along the sides. Air is propelled toward the peak of the shelter (that's why deflector panel is installed), mixed from both sides and ejected out each end. Air is stacked and velocity is created by compressing the air flow from 6 inches (15.2 cm) down to about 2.5'' (6.4 cm). Summer ventilation is assisted by air movement through the ends as well (see above illustration).