A hopper bottom for supporting a cylindrical side wall of a grain binincludes a hopper wall having an inverted cone shape supported on uprightsupportlegs. A manifold duct is supported above the hopper wall to define a manifoldpassagetherein extending circumferentially adjacent to the peripheral edge of thehopper wall.A plurality of outlet openings formed in the manifold duct in communicationfrom themanifold passage to an interior of the hopper wall for open communication withthegrain bin thereabove. An inlet opening extending through the hopper wall inalignmentwith the manifold duct receives ventilation air from a blower to direct theflow throughthe manifold duct and into the grain bin through the outlet openings of themanifold duct.
