Flue Size - Can I Go From 8" to ~ 6.5" Dia?

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DoubleClutch

Member
Jan 23, 2007
102
Virginia coast
Hello, all,

I'm planning to buy a used VC Defiant Encore 2140 to replace an aging VC Intrepid II.

I was comparing my Intrepid II Owner's Manual with one I downloaded for the Defiant Encore, and I see the Defiant Encore calls for an 8" flue and pipe.

I measured my flue pipe and it seems to be about 6.5" or 7" diameter.

The flue pipe is stainless steel (smooth, non-corrugated) and runs inside an old (1890s) brick chimney in an old farmhouse.

In total, the stack is probably 34' or 36' high, and exits the peak of the 12-pitch roof on this old farmhouse. I suspect that they installed the SS flue pipe, and then poured or packed vermiculite around it as an insulator, although I don't know for sure.

We live near the coast where it is usually windy (sometimes VERY windy) so the flue normally draws like a rocket engine, at least on the Intrepid II.

My question is, could I safely "step down" the VC Defiant Encore from its suggested/specked 8" flue down to my existing 6.5" or 7" flue in this situation?

The price on the stove is good, so I don't want to pass it up!

(On a related note, the house has a second, unused chimney of similar age, size and construction. I've considered adding a second wood stove but I'm not sure whether the chimney is big enough to accept 8" pipe...anyone know any rules of thumb on that?)

Sorry for the long post, TIA for any help and Happy New Year!
 
Sorry i cant help but am in a similar situation, Kindof. I have my insert running as a Slammer install. I am planning on lining it this spring i think, but my flue tiles are only about 6.5" at the narrowest and i have an 8" exit on my stove. My choice is to downsize or have an square liner (mega $$) or have one go up each Flue tile (there 2) and connect to a 8" pipe and a Y connector (crazy and no way). i have a chimney thats 25feet total and some here think i will be fine (as well as the manufacturer that i called and asked) to go to the 6" pipe esp for the height. I have a newer cat stove and they think it will help. For you i think you will be fine but i am far shy of an expert, but i think this as you say you have mega draft.
 
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