An HVACR fan and heater assembly accounts for the cyclonic flow produced by centrifugal blowers by placing a heater vertically and biased towards a side of a fan cabinet in order to increase and balance airflow through the heater, eliminating hot spots and fire risk and improving heater efficiency. A blockoff in the fan cabinet forces airflow within the cabinet to move through the heater. The positioning of the heater may vary depending on the direction of rotation of the centrifugal blower. The fan and heater assembly may further include baffles to direct the airflow from the centrifugal blower.