A Sub-Zero refrigerator is designed to maintain precise temperatures in both the freezer and fresh food sections. When the fresh food compartment starts feeling warmer than normal, food may spoil faster, condensation can appear, and the refrigerator may run more frequently. One common cause is a problem with the air damper or evaporator fan, both of which play an important role in distributing cold air. The fresh food section does not usually generate cold air independently. In many Sub-Zero models, cold air produced by the cooling system must be properly circulated into the refrigerator compartment. If that airflow is restricted, the freezer may remain cold while the fresh food section becomes noticeably warm.