8" outlet to 6" liner, issues?

[Hawch]

Hello,

I'm thinking of buying an Appalachian 32 XL BW insert. It has an 8" exhaust, yet I would have to use an adaptor to a 6" liner because my chimney isn't large enough for the 8". The manufacturer does not recommend this on this model and I've heard of problems with smoke coming into the room when reloading. That said, I wanted to get some opinions from those that have done this. I think I could be alright because I have a chimney just over 20'. Chimney is on the exterior, yet liner will have wrap insulation.

Thanks for your opinions,

 

[begreen]

I wouldn't do it. But there may be an alternative with and oval liner. What is the ID of the chimney?

 

[Hawch]

It is either 12" or 13" x 9"

 

[begreen]

M&G Duraliner 8" oval is 4 3/4" x 10 3/4"

 

[dmmoss51]

I like the oval idea... pi R^2 on an 8 inch outlet = just over 50 sqin. 12*9 = 108 sqin you should be able to get an oval in there without reducing the area of the flue below 50 sqin

 

[begreen]

And it's insulated.

 

[Hawch]

That's great advice, thank you. I just did a quick search online and can't seem to find this particular liner. I need 25', do you have a recommendation for where to buy this?