A thermal barrier apparatus for a window system includes a closed curve-shaped plate having a plurality of concentric channels, a plurality of walls each defining adjacent concentric channels, each of the walls including a plurality of openings between adjacent concentric channels, an outer wall formed on an outer peripheral edge of the closed curve-shaped plate, the outer wall including a plurality of openings, and an inner wall formed on an inner peripheral edge of the closed curve-shaped plate including a plurality of openings. The plurality of openings and concentric channels are configured to provide an air flow path for conduction of air through the thermal barrier apparatus to an exterior of the thermal barrier apparatus.