Patent ID: 7721794

Claim:
A heat exchanger assembly for use as a residential/industrial heating, ventilation, air conditioning refrigeration system that lies in the path of oncoming air, the assembly comprising: a plurality of heat transfer tubes; a plurality of fins, at least some of which being in contact with the plurality of heat transfer tubes; at least some of the plurality of fins having a predetermined array in which one or more fins has a predetermined pattern of louvers, the geometry of which is characterized by a dimensionless parameter F that is a function of louver pitch P L , louver angle α, and fin pitch P F , such that the tangent of the louver angle times the louver pitch divided by the fin pitch is between about 0.20 and 0.65, where 20≦P F ≦30 fins per inch; and wherein the tubes have longitudinal axes at a tube center thereof and the predetermined pattern of louvers associated with a fin is defined in relation to the centers of adjacent tube holes in the fins that receive the tubes, such that the louvers have end portions that lie at a constant radial distance r L from the tube axis, the louvers being parallel to an edge of the fin.