Patent ID: 7559211

Claim:
A refrigeration appliance comprising: a freezer compartment; a fresh food compartment; a refrigeration system, including an evaporator; an evaporator cover positioned between said evaporator and said freezer compartments having a first passage for discharging air cooled by the evaporator; a defrost heater associated with said evaporator; an air tower attached to said evaporator cover receiving cooled air discharged from the evaporator through said first passage, said air tower having a diffuser section overlying said first passage and having a plurality of vent outlets positioned in said freezer compartment for directing cooled air into said freezer compartment, a central vertical duct section defined by substantially vertical walls comprising a front wall and first and second side walls extending from said diffuser section for directing cooled air toward said fresh food compartment, an outlet at an end of said central vertical duct section opposite said diffuser section to communicate with said fresh food compartment, and a first heat trap compartment formed along said first side wall defining said central vertical duct section comprising a first additional wall spaced from said first side wall and connected to said first side wall at a first and second end forming a first enclosed space on the exterior of said central vertical duct section on said first side wall, wherein said evaporator cover has at least one second passage therethrough in a region corresponding to said first heat trap compartment to allow heat to flow into the first heat trap compartment from the defrost heater.