A method of manufacturing an aluminum heat exchanger comprising the steps of: providing a plurality of refrigerant tubes extruded of an AA3000 series Al alloy consisting of 0.90 to 1.10 wt% of Mn with the balance of Al and trace element impurities, the trace element impurities consisting of 0.3 percent by weight (wt%) max of Si, 0.20 wt% max of Fe, 0.03 wt% max of Cu; applying a Zn coating onto the exterior surface of at least one of said plurality of refrigerant tubes by pre-treating the exterior surface with either a reactive Zn flux, KZnF 3, delivered by a roll coated organic binder, or a mixture of elemental zinc powder and controlled atmosphere brazed flux by gas plasma or organic binder, providing a plurality of fins manufactured from an AA3000 series Al alloy having 0.3 to 1.0 wt% of Si, 0.4 wt% of Fe max, 0.05 wt% max of Cu, from 1.3 to 1.8 wt% of Mn, between 1.2 to 1.8 wt% of Zn, and 0.20 wt% max of Zr; providing at least one header manifold having a plurality of refrigerant tube slots, wherein said at least one manifold is formed from an AA3000 series Al alloy sheet having a AA 4000 series Al cladding formulated with Zn at 0.9 to 1.1 wt%, wherein said AA 4000 series Al alloy sheet includes a core having 0.6 wt% max of Si, 0.7 wt% max of Fe, from 0.05 to 0.65 wt% of Cu, from 1.0 to 1.6 wt% of Mn, 0.20 wt% max of Mg, 0.10 wt% max of Zn, and 0.25 wt % max of Ti; assembling said fins between adjacent pairs of said refrigerant tubes; inserting the open ends of said plurality of refrigerant tubes into corresponding said refrigerant tube slots of header manifold, thereby forming a heat exchanger assembly; applying a CAB flux externally on the header manifold for the tube-to-header manifolds before brazing; and heat treating said heat exchanger assembly at a sufficient time and temperature to braze said plurality of refrigerant tubes, fins, and said at least one header manifold into a single unitary structure, and to diffuse said Zn coating into said refrigerant tubes to form a Zn diffusion layer, wherein said step of said applying a Zn coating onto the exterior surface of at least one of said plurality of refrigerant tubes includes applying Zn at 4 to 6 g/m 2 to greater than 85% of said surface area of refrigerant tube before brazing to obtain said Zn diffusion layer having a thickness of less than 85 μm and having 1 to 3 wt% of Zn after brazing. providing a plurality of refrigerant tubes extruded of an AA3000 series Al alloy consisting of 0.90 to 1.10 wt% of Mn with the balance of Al and trace element impurities, the trace element impurities consisting of 0.3 percent by weight (wt%) max of Si, 0.20 wt% max of Fe, 0.03 wt% max of Cu; applying a Zn coating onto the exterior surface of at least one of said plurality of refrigerant tubes by pre-treating the exterior surface with either a reactive Zn flux, KZnF 3, delivered by a roll coated organic binder, or a mixture of elemental zinc powder and controlled atmosphere brazed flux by gas plasma or organic binder, providing a plurality of fins manufactured from an AA3000 series Al alloy having 0.3 to 1.0 wt% of Si, 0.4 wt% of Fe max, 0.05 wt% max of Cu, from 1.3 to 1.8 wt% of Mn, between 1.2 to 1.8 wt% of Zn, and 0.20 wt% max of Zr; providing at least one header manifold having a plurality of refrigerant tube slots, wherein said at least one manifold is formed from an AA3000 series Al alloy sheet having a AA 4000 series Al cladding formulated with Zn at 0.9 to 1.1 wt%, wherein said AA 4000 series Al alloy sheet includes a core having 0.6 wt% max of Si, 0.7 wt% max of Fe, from 0.05 to 0.65 wt% of Cu, from 1.0 to 1.6 wt% of Mn, 0.20 wt% max of Mg, 0.10 wt% max of Zn, and 0.25 wt % max of Ti; assembling said fins between adjacent pairs of said refrigerant tubes; inserting the open ends of said plurality of refrigerant tubes into corresponding said refrigerant tube slots of header manifold, thereby forming a heat exchanger assembly; applying a CAB flux externally on the header manifold for the tube-to-header manifolds before brazing; and heat treating said heat exchanger assembly at a sufficient time and temperature to braze said plurality of refrigerant tubes, fins, and said at least one header manifold into a single unitary structure, and to diffuse said Zn coating into said refrigerant tubes to form a Zn diffusion layer, wherein said step of said applying a Zn coating onto the exterior surface of at least one of said plurality of refrigerant tubes includes applying Zn at 4 to 6 g/m 2 to greater than 85% of said surface area of refrigerant tube before brazing to obtain said Zn diffusion layer having a thickness of less than 85 μm and having 1 to 3 wt% of Zn after brazing.