Continuing with some old easy exam questions on Heating …
The enclosed passageway through which smoke and other gasses from combustion move upward is known as the:
The correct answer is …
A. flue
Note that a chimney is “A structure containing one or more flues for removing gases to the outside atmosphere” … http://www.nachi.org/glossary/c.htm
Chimney would be correct for early century double brick construction with no flue.
Although that type construction is antiquated by today’s standard. :mrgreen:
Correct ;-)
That is why when people say will this meet code. I say which one.
Actually the chimney would still technically be the structure, and the passageway formed by the bricks would be the flue … although it would be an unlined passageway … 
Check the IRC definitions for “chimney” and “flue”
I am well aware of the technical definitions. 
So thats why the correct answer for the “passageway” would be … A. flue …
I know, that is what I voted on. Doesn’t dismiss the fact that chimneys with no flue actually had a brick flue. :mrgreen:
I think ya meant that a chimney with no “flue liner” actually has a flue formed by the bricks … :mrgreen:
But the “passageway” formed by the bricks is still the flue, and the brick structure is still called the chimney …