What is a "vertical vent stack"? A picture for comparison would be useful for non-specialists. Drutt (talk) 20:23, 23 August 2008 (UTC)
The diagram here is very good. Clearest reference on the web. I was googling for the history of why it is called a Chicago Loop. Anyone have a history reference? Kd4ttc (talk) 03:44, 3 November 2013 (UTC)