Stove pipe reducer/increaser question

[mkarlson]

I recently purchased a used earth stove 100 series. The flue is on the top an appears to be 8" reduced to a 6" with a fitting. Of course the fitting is crimp end up. I would like to know if I purchased a 8x6 with large end crimped if it would be a better way to go? This is my first install and trying to do it the right way. Everything I read says to put crimp end down so creasote will go into stove and not leak out on to pipe. That being said I see alot of stoves with crimp end up? Is there a reason for this or just a practice from back when?

 

[Shane]

General rule of thumb is to never downsize a stoves flue. If it's 8" off the top it needs to be an 8" chimney. Whether or not it will work in the real world is a matter of chimney height, house pressure and luck but the common result will be smoke filling your home. There are a few exceptions where stoves can be used with either 8" or 6" flues, but, unless you have an owners manual telling you your stove is one of these I really wouldn't recommend downsizing the flue.

 

[mkarlson]

Thanks for the reply. I have no manual with this stove. I dont know for sure but the 4 or 5 pictures I've seen of others( on this forum and others) stoves they all have the reducer. Maybe it came from factory like that. My concern is the creosote. Just seems like it would be easier to replace the adaptor at the stove and be done with it.

 

[Shane]

If your going to decrease the flue size then the adapter you have pictured above would be what you want. Really would be a shame to invest the time and money in a 6" chimney to have it not draft properly though.

 

[mkarlson]

Wish I had a manual. Looked over couple pictures and I was wrong I've heard or have seen both 6" and 8" pipe. I dont want to change anything. I want to get it right though. This stove is used and had the reducer already installed. After closer inspection it is a thinner guage metal than what is comming out of the stove. So if I choose to remove the reducer thats currently on the stove it would solve the pipe direction problem, is there an issue with using a too large of pipe? I assume if I use 8" out of the stove I should keep 8" all the way through chimney also?

 

[mkarlson]

Sorry for asking such newbie questions, but like I said its my first wood stove. I've been cutting and selling firewood for years. Only using a little of it for camping. Will be nice to finally get to heat my house at least partilly with wood.

 

[Shane]

You can have too large of a chimney, say if you were dumping that stove into a 13x17 terra cotta or something, there's a great article on flue sizing in the information section. It points out that while the difference between 6" & 8" doesn't sound like that much the 8" pipe is actually has almost twice the cross sectional area. The 8" should work optimally, the vast majority of stoves from that era used 8" chimneys and if it's the Earthstove that I'm thinking it is then all of them that I've seen were on 8" chimneys. And yes, you'll want to maintain the 8" diameter throughout the entire system. And don't worry about the "newbie" questions that's what this place is here for.

https://www.hearth.com/what/specific.php

How to install a wood stove article under the Wood Appliances heading and the Chimney sizing is under General Chimney Information Heading.

 

[mkarlson]

Thanks for all the replies. I will remove current reducer and go with the 8" pipe and chimney.