A refrigerator appliance includes a rear wall, side walls, a bottom wall, and partitions. The side walls are secured to and extend from the rear wall toward a front side of the refrigerator. The bottom wall is secured to the side walls along a bottom end of the rear wall. The side walls and the bottom wall define a cavity below the bottom wall and define an opening to the cavity along the front side of the refrigerator. The rear wall and the bottom wall define a machine compartment. An exterior surface of the rear wall defines an inlet to and an outlet from the machine compartment. A first partition extends outward from the exterior surface and is disposed between the inlet and the outlet. A second partition extends from a bottom of the first partition. The partitions are configured to segregate airflows between the inlet and outlet.