fintubes

Fin tubes, or finned tubes, are heat exchanger tubes with external fins that increase the surface area available for heat transfer between a fluid inside the tube and the surrounding medium. They are commonly used where air cooling is involved, such as condensers, radiators, and air-handling units.

The basic construction is a hollow tube with attached fins. Fins can be integral (extruded with the tube) or mechanically bonded, weld/brazed. Fin shapes vary, including flat rectangular, wavy, or louvers. Fin density (fins per inch) and fin height are chosen to optimize heat transfer and allowable pressure drop, while balancing fouling risk. Materials are typically aluminum, copper, or stainless steel, with aluminum being dominant in many HVAC applications.

Manufacturing methods include extrusion of aluminum with embedded fins, mechanical bonding of separate fins to the tube, brazing or welding of fins, and assembling finned tubes into a tube bank. Fin geometry and tube pitch determine airflow patterns and performance.

Applications cover automotive radiators, air conditioning condensers, heat exchangers in industrial processes, and air-cooled power plant condensers. Advantages of fin tubes include increased heat transfer surface area in a compact form and improved efficiency; drawbacks can include higher manufacturing cost, greater susceptibility to fouling, and increased pressure drop.

See also: Heat exchanger, finned tube, louvers, extruded aluminum heat exchanger.