I suspect you will be wanting all eight inches of chimney diameter working for you during the bake down phase. Starting from a cold stove, once the combustor reaches the active zone you'll want to engage the combustor and run the throttle wide open for 30 minutes.
This is what I think of as the "bake down" phase. As the fuel in there gets hotter and hotter you will be baking the last of the moisture out of the cordwood, literally _baking_ the fuel not on fire yet _down_ to zero moisture content.
For this phase you need a lot of heat in the chimney to lift the weight of all that water, and you want the chimney hot all the way up so you are ejecting water vapor, not having a bunch of condensate form on the inner walls of your chimney.
M2c
Thanks, Poindexter. I like this kind of reply. You're talking about principles, not just reciting rules. I like that. I've seen a lot of things done that people were sure couldn't be done. Some of those people never took the time to question the conventional wisdom or to contemplate the ultimate goal of whatever it was they were doing.
If I could speculate a bit...
If one of the purposes of the chimney is to carry water from the wood out into the atmosphere without a lot of condensation in the chimney, is a bigger chimney necessarily better suited for the job than a smaller one?
What if, instead of 6" vs. 8", we imagined 2" vs. 12"? Which one would expel water better?
If the two chimneys have identical layout and rise, and if they are being fed by identical stoves burning the same quantity of wood at the same temperature, then they should have identical pressure, right? (Please ignore for now the fact that the stove won't be able to "breathe" anywhere near as well with the 2" chimney, and so won't be able to burn the same fire as the one with the bigger chimney.) The bigger one just pulls a greater volume of air at the same velocity, right? This isn't a rhetorical question. My knowledge of physics comes almost entirely from experience rather than from formal training.
Intuitively, I'm gonna say that, all else being the same, the bigger chimney will run cooler than the smaller one, and will therefore be more likely to have condensation. But, maybe, since the bigger chimney is allowing the stove in "inhale" more air, the humidity of the exhaust is lower.
I will also say that it seems likely that the stove hooked up to the chimney of a size and type *that its designers specified* is more likely to run optimally.
I realize that the engineers who designed my stove probably know a lot of things that I don't know. I haven't even seen a stove like this run, so I'm sure I have something to learn. Part of my willingness to cut corners here is the instant vs. delayed gratification. I'd hate having to make a place in my garage for that Blaze King and then have to dig it out next summer. I'd rather put it in my living room and start playing with it now, but I really would rather wait until summer to climb up on my roof.
But this is probably all academic. I am about this far from ordering the chimney and everything else I need for an 8" install. Everything's in the shopping cart. It'll be a fun install. And I won't fall off the roof. I hope.
Thanks for the helpful reply.
Brent