An arrangement for drying air, particularly for a compressed air installation of a rail vehicle, includes an air dryer that receives air that is to be dried, via an air dryer inlet. In order to optimize the arrangement with regard to external conditions prevailing in the region of a rail bound transportation route to be travelled, an air conditioning installation is provided that supplies air to an air conditioning installation outlet, the air dryer inlet being connected, by way of an air channel particularly designed as an air conduit, to the air conditioning installation outlet such that at least one portion of the air supplied from the air conditioning installation forms the air that is to be dried. The invention also relates to a rail vehicle that includes such an arrangement, and also to a method for drying air.