US Patent 10208964 Steam cooking oven and method

A method for reducing energy consumption in a steam cooker that includes a steam cooking cavity, a steam generator for delivering steam along a steam path to the steam cooking cavity, a steam outlet from the steam cooking cavity to a first flow path leading to a drain path. The method involves: (a) utilizing a second flow path from the steam outlet to a vent stack to deliver excess steam flows from the steam cooking cavity up the vent stack rather than down to the drain box; (b) sensing temperature within the vent stack; and (c) utilizing sensed temperature within the vent stack to regulate power of a heating unit of the steam generator to produce steam in a controlled manner that reduces flows of excess steam out of the steam cooking cavity.