Abstract: A window system for defrosting the windows of a vehicle comprises a windshield assembly having first and second spaced-apart panes of glass with an interlayer of air space therebetween. A frame surrounds the panes and maintains the air space therebetween. An inlet extends through the bottom wall of the frame for entry of air between the windshield panes. An outlet extends through a side wall of the frame for discharging air from between the windshield panes. The system also includes a plurality of window assemblies, each window assembly including first and second panes with an air space therebetween. An inlet extends through one side of the window frame for entry of air between the window panes. An outlet extends through an opposed side of the window frame for discharge of the air therefrom. The inlets and outlets of the windshield and window assemblies are positioned such that air may freely pass between adjacent assemblies through channels extending through vehicle support posts.