Air flow ducts for improving the air flow within data processing units are described herein. In some embodiments, a duct includes an inlet portion and an outlet portion. An interior surface of the outlet portion of the duct defines, at least in part, a portion of a flow path. The duct is configured to be coupled to a printed circuit board within a data processing unit such that a first portion of a cooling fluid can flow within the flow path between the inlet portion of the duct and an electronic device coupled to the printed circuit board. An exterior surface of the outlet portion of the duct is configured to redirect a second portion of the cooling fluid to a volume within the data processing unit apart from the electronic device.