An isothermal turbo-compressor-condenser-expander (ITCCE) includes heat-transferring fan blades that are mounted on, or surround, individual conduits to promote air exchange and heat transfer. In operation, the open framework rotates in free air to promote heat exchange. An ITCCE bladed assembly includes a driven central hub assembly with a first fluid coupling. A first inner plenum is in fluid communication with the fluid coupling. A plurality of compressor multiport conduits extend radially, and pass fluid from, the first inner plenum to an outer plenum that acts as an equalizing line. A return path is provided to the fluid coupling from the outer plenum. The conduits can be formed as metal extrusions, including internal ribs that separate a plurality of ports formed therebetween along an entire length of the conduits. The conduits can define an airfoil shape and/or are axially twisted, generating axial airflow. The return path can include return multiport conduits.