A reflow oven chamber assembly that is configured to be installed within a reflow oven chamber of a reflow oven includes a chamber housing disposed within the reflow oven chamber, one or more heating elements disposed in the chamber housing, and one or more compression box assemblies disposed in the chamber housing. The compression box assembly includes a compression box housing having an intake port located adjacent the heating element, an intake duct disposed in the compression box, and a diffuser plate disposed above the intake duct. The intake duct has an inlet opening in fluid communication with the intake port of the compression box housing and an outlet opening. The compression box assembly is configured to draw heated air into the compression box housing from the reflow oven chamber through the intake port and into the inlet opening of the intake duct and exhaust air out of the outlet opening of the intake duct to the diffuser plate. A method of distributing heated air within a reflow soldering oven is further disclosed.