A thermal ducting rail receives a rack device in a rack chassis. The thermal ducting rail includes air flow guiding elements that enable cooling air from a front face of the rack chassis to be directed to an external side of the thermal ducting rail and from the external side to a rear face of the rack chassis. The thermal ducting rail enables rack devices equipped with side-to-side cooling to receive cooling air in a rack chassis with front-to-back cooling, without extending beyond a unit height occupied by the rack device.