Chimney question: what is this?

DEL1889

I’m not a professional; just a resident. I have hot water radiator heating with a boiler. Boiler is in the basement, with a flue. In the master bedroom there is a vent which I always assumed was a vent for the chimney. But when I open it I can see that it’s not open on the top. Only on the bottom. I suspect it’s a abandoned flue (the fireplace was sealed years ago) - maybe to deliver heat to the bedroom from the fireplace. Anyone know what this is? Can I just seal it up? Pictures attached. Third one is the top (sealed). It’s like a box that is only open on the bottom. It looks like it had a latch / device that used to allow it to be closed shut (remnants on the left side). Thanks!!

bburd

That looks like an old hot air heating supply stack head. When hot air heat was added to existing homes, ductwork to upper floors was often run alongside a chimney. What's puzzling is that it looks like piping was run through it later on.

How old is the house, and are there any other signs of a previous heating system before the hot water heat went in?

DEL1889

https://forum.heatinghelp.com/discussion/comment/1835028#Comment_1835028

Thanks for the reply! Our best guess is that the house was built around 1885-1890. It’s an old Philadelphia row-home. I am not aware of any other signs of previous systems - I assumed it was always radiator heat, but I have no evidence of that. In fact, I can see scars on some floors where older radiators were removed / moved. As said, it’s above the fireplace (sealed up for awhile now, by previous owners). It does indeed look like it had the ability to be closed, similar to how a more modern register can be closed. There are about 20 houses with my exact layout in a row on my block - I’ll ask a few neighbors if they have anything similar. Nothing like it appears in any other room in my house. Thanks again. 

Edited to add: AC was added to the house (reportedly in the 1990s), and new duct work was installed for that. I know no old / existing systems were used for that.

bburd

@DEL1889 you asked in your initial post if you could just close that opening off. I don't see why not. The closure should be non- combustible. Old ductwork like that is typically closed off with sheet metal.

Long Beach Ed

Yes, that is an old hot air heating outlet. Look around the basement and you'll probably see more signs of the old round duct work. Commonly installed in the 'teens and often replaced by steam in the 1930s. You may have more outlets covered up in other rooms.

DEL1889

https://forum.heatinghelp.com/discussion/comment/1835416#Comment_1835416

Thank you!!!

EBEBRATT-Ed

Check inside for hidden money before you seal it up😊😊

Lance

Actually in Baltimore the flues became the air duct. Cheap and easy, however many suffered from the sooty deposits breathing the air when entering bedrooms. Nobody lined them.