Duct Connected to Chimney

Hi guys, any idea what’s going on in this configuration? Duct connected to chimney, looks like a return vent? This is a new one for me.

House built in the 1960’s…




Don’t know what it may be, but there should not be any appurtenant devices, ducts, etc., connected to a chimney that might negate it primary function and fire resistive qualities.

And on a side note, I like the innovation of that chain pipe hanger. ;):slight_smile:

It looks like old framing…probably and old house. Was there a fan? Were they trying to get a little heat off the chimney for the upstairs bedroom? They don’t think about what would happen when the old chimney leaks. :shock: