A finned tube heat exchanger is a type of heat exchanger that enhances heat transfer between two fluids by increasing the surface area available for heat exchange.

Finned tube heat exchangers consist of a bundle of tubes with external fins attached to the tube surfaces. The tubes carry one fluid stream, while the fins extend from the tube surfaces to increase the surface area available for heat transfer to or from the surrounding fluid. The fins are typically made of materials such as aluminum or copper.

Heat transfer in finned tube heat exchangers occurs through conduction across the tube walls and convection between the fluid streams and the fins. The fins increase the surface area of the tubes exposed to the fluid flow, facilitating efficient heat transfer between the fluids.