I found this unit on a very old boiler (at least 1969) yesterday. I don’t see how this could possibly promote proper draft. Wouldn’t a column of cold air in the winter force combustion gases out into the living space?
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I wonder is some thing missing like a cover full of u shaped tubes and then it could be a heat reclaimer ?
Roy Cooke
Roy - It didn’t seem like anything was missing. I’ve seen open end systems like this but they have always had an appropriate slope to facilitate venting.
I think Roy is right,
To me it looks like a barometric damper without the flap to regulate the draft.
I will agree with Roy here. It looks like a cover of some type is supposed to be over the opening. Perhaps it was removed a long time ago to provide heat to the adjoining space.
The unit looks old and I would write it up for evaluation/repair by a qualified HVAC technician. The way it looks it must be venting combustion products into the surrounding area.
I considered that too but I do not see any pivot holes for the damper. I also am assuming this is gas fired because of the black pipe I see in the photo.
There were no holes for a damper or anything else. It is a gas-fired boiler and it was written up for further evaluation. It’s basically an old piece of cr*p that needs to be turned into a boat anchor. Thanks for the answers guys.