Abstract: The present invention is directed to a finned heat exchanger comprising an inner annulus, an outer annulus, a plurality of fins, and an outer chamber. The plurality of fins extends radially outward from the outer surface of the inner annulus toward the inner surface of the outer annulus. The outer chamber is located between the inner annulus and the outer annulus. The plurality of fins is located within the outer chamber. A method of heating or cooling a fluid using the finned heat exchanger and a method of forming the finned heat exchanger are also disclosed.