Every once in awhile I check out the Woodstock Soapstone site to check out their Keystone stove. (could be my next stove)Today I noticed something I haven't before. The Keystone and Palladian stoves both require a 7" flue? What's up with that? Their two larger models, Fireview and Classic take a 6" flue, and have larger fireboxes. Any of you Keystone owners out there have any info on this?