According to one example, a convection oven comprises a cooking chamber having a front door and a rear door opposing the front door; a combustion chamber disposed below at least a portion of the cooking chamber; a side flue conduit configured to direct hot air from the combustion chamber to the cooking chamber; and a side sub-chamber with a convection fan configured to re-circulate at least a portion of the hot air within the cooking chamber, in which the side sub-chamber is disposed adjacent a side of the cooking chamber that is orthogonal to the front and rear door.