A furnace system featuring baffles, each set of baffles including one or more movable vanes, and systems for controlling the positioning of movable vanes during furnace operation. Actuators may be used to move vanes between deployed and retracted positions, the actuators controlled by units within the furnace or linked to the power sources for furnace elements which are specific to either heating or cooling operations. The movable vanes may alternately be positioned by using springs with stiffness selected to place vanes in a deployed position when under heating airflows and in a retracted position when under cooling airflows.