A method of constructing an air handling unit includes forming an air handling enclosure, mounting a blower in the air handling enclosure, mounting a heat exchanger in the air handling enclosure downstream of the blower, and mounting at least one heating element in the air handing enclosure downstream of the blower. A method of operating an HVAC system includes disposing a heat exchanger downstream of a blower within an enclosure, providing an airflow through the enclosure, and orienting a plurality of fins on the heat exchanger to stabilize the airflow exiting the heat exchanger prior to the airflow contacting an electrically-powered resistive heating element.