From what I see, I think they use aluminium in air conditioner tubing and fins...
Copper conducts heat better than aluminium, but heard that aluminium is better for the fins as the heat releases to the air better from aluminium than copper.
Gold is incredibly malleable and can be made really thin... how malleable, strong is copper compared to aluminium for say doing multiple thin windings as required in electric motors?
Notice that car radiators that were once copper are now plastic and (?)aluminium....
