Early A A/C how well does it work

Factory a/c showed up during 65 model year, these cars had an integrated unit with pushbutton controls. Earlier cars had dealer installed units which operated separate from the heater and were not fresh air capable. My argument with most of the "hot rod" a/c systems is that they do not ingest fresh air. Much as I like the smell of my own farts, even chilled and recirculated they get old after a few.