Stove Pipe Sizing - 30NC

[mikedsvt]

So I need to decide what is best to do for piping the 30NC to my chimney....

I Currently have a VC Vigilant with a oval hook up to a 8" Pipe. The 8" pipe is reduced at the chimney to a 6" inlet for the flue.

Should I buy a reducer and choke the 8" down to a 6" before the stove hookup and use the 8" existing pipe?

Or should i get all new 6" piping and use 6" from the stove all the way to the chimney?

I was curious as to what setup may work best and if it worked anything like a down pipe on your car. Maybe a smaller pipe would create a better draft/flow or would a larger pipe?

 

[fossil]

An 8" pipe has nearly twice (~1.8x) the cross-sectional area of a 6" pipe. As the flue gas flow transitions from 6" to 8", the mass flow rate will drop considerably. This will likely have two consequences, neither of them desireable. Your stove will not draw as well, and the flue gases will spend more time cooling down getting up the chimney to daylight, increasing the likelihood of creosote condensation. Rick

 

[begreen]

Considering this is a basement install, I'd put in new 6" double-wall from the stove to the chimney to keep the flue gases hotter and a cleaner installation.

 

[Jags]

Yep, don't mess around with the adapters any more than you need to. Go 6" from stove to chimney and it should treat you well.