A modular radial impeller drum for cooling print media in a printing device are disclosed. For example, the modular radial impeller drum includes a plurality of impeller modules coupled together to form a surface to transport the print media. Each one of the plurality of impeller modules includes a cylindrical outer surface, a cylindrical center axis inside of the cylindrical outer surface, and a plurality of impeller blades coupled between the cylindrical outer surface and the cylindrical center axis, wherein the plurality of impeller blades the plurality of impeller modules is varied across a length of the modular radial impeller drum.