I have three circular cast iron vents in my upstairs bedrooms (one in each room) that I can't quite figure out. They seem to be placed where the chimney comes up through the house but Im not sure if they are actually connected somehow. (The fireplace is downstairs.)
It seems strange that the chimney would vent directly into the rooms upstairs. My first thought was to light a fire in the fireplace, and open the vents up but there are cracks in the masonry so I'm a little weary of that. We've never used it.
Anyone have similar vents?