Technologies for providing a gas inlet and gas outlet to a compartment are described. In embodiments, the technologies include a dual channel connector unit that includes an inlet passageway and an outlet passageway. In embodiments at least a portion of the outlet passageway is disposed radially around the inlet passageway. The connector unit is configured to install into a portion (e.g., wall, bottom, top, or lid) of a compartment. Systems and methods including such connector units are also described.