Todays inspection, the buyer was wondering how it was possible that the original (1956) furnace was still in the house.
Furnace was working great, no CO, note the heat exchanger! Looks like you could use that for an atomic reactor.
Note the input output rating plate, apparently that furnace is about 84% efficient according to the rating plate (!!!) I realize that ain’t AFUE, but still.
In many ways it more resembles the old gravity furnace especially the solid construction of it, but it is forced air, quite low velocity but forced air.
If it was mine I would keep it, probably for ever.