An additive manufacturing system, comprising: a housing defining a chamber, wherein a lower portion of the chamber comprises a build platform disposed therein that is configured to receive a powder material; a gas inlet system coupled to a first side wall of the housing and configured to direct one or more gas flows (252, 262) through the chamber; a gas outlet defined in a second side wall of the housing, disposed opposite the first side wall, wherein the gas outlet is configured to discharge the one or more gas flows (252, 262) from the chamber; characterized in that the system comprises: a spacer flow guide disposed within the chamber and configured to direct the one or more gas flows (252, 262) around the spacer flow guide; and a main exhaust channel defined between a first surface of the spacer flow guide and the housing, wherein the main exhaust channel is configured to direct a first portion of the one or more gas flows (252, 262) from the lower portion of the chamber into the gas outlet; and a bypass exhaust channel defined between a second surface of the spacer flow guide and the housing, wherein the bypass exhaust channel is configured to direct a second portion of the one or more gas flows (252, 262) from an upper portion of the chamber to combine the first portion and the second portion of the one or more gas flows (252, 262) upstream of the gas outlet. a housing defining a chamber, wherein a lower portion of the chamber comprises a build platform disposed therein that is configured to receive a powder material; a gas inlet system coupled to a first side wall of the housing and configured to direct one or more gas flows (252, 262) through the chamber; a gas outlet defined in a second side wall of the housing, disposed opposite the first side wall, wherein the gas outlet is configured to discharge the one or more gas flows (252, 262) from the chamber; characterized in that the system comprises: a spacer flow guide disposed within the chamber and configured to direct the one or more gas flows (252, 262) around the spacer flow guide; and a main exhaust channel defined between a first surface of the spacer flow guide and the housing, wherein the main exhaust channel is configured to direct a first portion of the one or more gas flows (252, 262) from the lower portion of the chamber into the gas outlet; and a bypass exhaust channel defined between a second surface of the spacer flow guide and the housing, wherein the bypass exhaust channel is configured to direct a second portion of the one or more gas flows (252, 262) from an upper portion of the chamber to combine the first portion and the second portion of the one or more gas flows (252, 262) upstream of the gas outlet. a spacer flow guide disposed within the chamber and configured to direct the one or more gas flows (252, 262) around the spacer flow guide; and a main exhaust channel defined between a first surface of the spacer flow guide and the housing, wherein the main exhaust channel is configured to direct a first portion of the one or more gas flows (252, 262) from the lower portion of the chamber into the gas outlet; and a bypass exhaust channel defined between a second surface of the spacer flow guide and the housing, wherein the bypass exhaust channel is configured to direct a second portion of the one or more gas flows (252, 262) from an upper portion of the chamber to combine the first portion and the second portion of the one or more gas flows (252, 262) upstream of the gas outlet.