I found this spreadsheet while searching for draft info. It is a draft calculator and stove modeling tool created in Excel.
http://www.bioenergylists.org/stovesdoc/Crispin/draftcalc.htm
I haven't played with it yet, but it seems pretty inclusive as to most of the common variables found in various installs and burning scenarios. If you can figure out how to use it, it may give some theoretical answers to questions regarding flue problems encountered in marginal installations. You can download it from this page, but you must un-protect it before you can change cell contents to actually use it. Just go to the "Tools" menu in Excel and go to the "Protection" sub-menu and click "Unprotect sheet" (no password is required). This is a screen capture of what it looks like:
http://www.bioenergylists.org/stovesdoc/Crispin/draftcalc.htm
I haven't played with it yet, but it seems pretty inclusive as to most of the common variables found in various installs and burning scenarios. If you can figure out how to use it, it may give some theoretical answers to questions regarding flue problems encountered in marginal installations. You can download it from this page, but you must un-protect it before you can change cell contents to actually use it. Just go to the "Tools" menu in Excel and go to the "Protection" sub-menu and click "Unprotect sheet" (no password is required). This is a screen capture of what it looks like: