Our Ancona range hood models are designed to eliminate the odors and are not constructed to push air back into the home. The motor runs one way only and usually, if the air is blowing downwards is because there is obstruction in the ventilation tube. Please check if the damper on the unit is opening and closing properly.  The damper flaps must be removed in order to have a better suction power and an effective air flow. Also, please make sure that the ventilation tube is not clogged i.e rocks, leafs, dust etc.