The disclosed system provides heat and/or moisture transfer between two counter-flowing air streams. The system comprises: a frame; a transfer wheel having a periphery spaced from the frame so as to form a gap therebetween, and including a transfer matrix mounted and rotationally secured relative to the frame so that the wheel can simultaneously rotate through the two separate, counter-flowing air streams; a sealing arrangement configured so as to seal the transfer wheel to the frame so that as the wheel rotates through the two separate counter-flowing air streams, the two air streams flow through the transfer matrix while remaining sealed from one another; and an electromagnetic actuator including rotational components secured relative to the wheel configured to generate flux across the gap and stationary components secured relative to the frame configured to impart a tractive force to the rotational components in response to polyphase power supplied to the stationary components.