WARNING: This page is about a different car, the 1999 Pontiac Firebird and 1999 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
In defrost blend position, air is distributed to floor, windshield and side windows. In defrost position, air is distributed to windshield.
Fig 1: Identifying Control Panel Settings (Typical)