A heat recovery wheel for a heat exchanger includes a wheel rim defining an outer perimeter of the heat recovery wheel, and a plurality of wheel passages located between the wheel rim and the wheel axis. The plurality of wheel passages are at least partially defined by one or more passage fins. At least a portion of a passage fin of the plurality of passage fins extends non-parallel to the wheel axis between a first wheel end and a second wheel end. The plurality of wheel passages are configured for flow of a first airflow and a second airflow therethrough for thermal energy exchange between the first airflow and the second airflow.