A cross-flow heat exchanger, method of making a cross-flow heat exchanger, and a dehumidifier are provided. The cross-flow heat exchanger has an axial flow path extending through the heat exchanger from an inlet to an outlet and a transverse flow path oriented transversely to the axial flow path and extending through the heat exchanger from an inlet to an outlet. The transverse flow path is adjacent to and separate from the axial flow path. The surface area of the inlet of the axial flow path is less than the surface area of the outlet of the axial flow path. In a preferred embodiment, the heat exchanger has an exterior shape that is trapezoidal.