An air cleaning system for an oven that includes a cooking chamber configured to receive a food product includes a catalytic converter, an input array and a preheater. The catalytic converter may be configured to clean air expelled from the cooking chamber. The input array may include perforations through which cleaned air that has been processed by the catalytic converter is provided into the cooking chamber. The preheater may be disposed proximate to the cooking chamber to use heat generated by the cooking chamber to preheat the cleaned air prior to entry of the cleaned air into the cooking chamber through the input array.