Originally posted by Honorable_D:

Those chimneys aren't actually letting any smoke out in your screenies though. The roof piece over them is too low. I'd bet only a rare few smoke particles escape.

Actually they are. The chimneys that have fires in them currently are clearly venting smoke. The ovens, smelter, kiln, and blast furnace weren't in use at the time I took the screen shots so no smoke venting from those.