US Patent 6943322 Pressure exhaust system for a convection cooking appliance

A cooking appliance incorporates a convection heating system including a housing having an interior portion, a fan assembly, a heating element and an exhaust outlet duct. The exhaust outlet duct, within which is arranged a plurality of controlled vent openings, is positioned in a high pressure area of the convection heating system established about a periphery of the fan assembly and heating element. Oven gases are forced by the high pressure through the exhaust duct, thereby creating a corresponding reduction in pressure. The reduction in pressure establishes a low pressure area within the fan assembly which draws in fresh air in an amount equal to that exhausted through the exhaust duct.