This is some type of fan or blower that was in a utility room in a 70’s house? It was no longer being used, what is it?
Just guessing but it would have nothing to do with the dryer correct?
What is on the other side of this?
Looks like a vacuum.
Central vacuum with canister missing
It used to be vented to the exterior but they removed whatever was there and spray foamed the hole. A central vacuum makes sense but there were no suction pipes installed anywhere in the home. Maybe they just attached a long hose to this??
Maybe. An unprofessional installation for sure.
I was just curious. Home from the 70’s are typically the ones that have odd appliances or devices that have been abandoned.