Patent ID: 7913750

Claim:
A heat exchanger assembly comprising: an upper manifold extending along an upper centerline; a lower manifold extending along a lower centerline; said manifolds being spaced form one another with said centerlines being parallel to each other; said upper manifold defining a plurality of upper tube slots being spaced along said upper centerline; said lower manifold defining a plurality of lower tube slots being spaced along said lower centerline and aligned with said upper tube slots; a plurality of tubes having tube sides and extending between ends thereof in said upper and lower tube slots and parallel and spaced from one another; a plurality of fins each extending back and forth between and along said flat sides of adjacent ones of said tubes in a continuous serpentine path; each of said fins including a plurality of legs extending between said adjacent ones of said tubes and a plurality of end portions extending along said tube sides said adjacent ones of said tubes to define said serpentine path so that adjacent legs are connected by one of said end portions along one said tube and are open to the opposite adjacent tube to define a tube space between said adjacent legs along said tube sides of said tubes; and a plurality of spaced projections extending inwardly from said end portions of said fins between said legs, wherein said tube sides are flat and said tubes include a plurality of spaced protrusions extending outwardly from said flat tube sides of said tubes into said tube space between said legs, and wherein said projections and said protrusions are axially aligned in such a matter that air flow through said tube space is disrupted by said projections cooperating with said protrusion to break the airflow and thermal boundary layers, thereby improving total heat transfer.