A flush-mounted fireplace assembly comprising a surround structure configured to encompass a perimeter of an opening in a mounting wall and a bezel structure configured to fit within the outer surround structure. An inner edge of the surround structure and an outer edge of the bezel structure oppose each other and define a gap between inner edge and outer edge such that air can flow through the gap. An outside major surface of the surround structure and an outside major surface of the bezel structure are substantially co-planar with each other and with an exterior surface of the mounting wall.