liner sizing question. Advice needed!

[rsr347]

Hey all new to the forum looking for some solid advice. So here goes


My situation:
I have electric heat in my home and i have two wood stoves to help negate the home heating oil bill
Both wood stoves have outside air exchanges plumbed into them.
Last year i noticed smoke coming from the mortar gaps in between the bricks on the outside of the chimney.
I was told to have the flues relined with stainless steel liners.

My issue is both of the flues are round 6" terracotta flues and are completed cemented in the chimney from top to bottom with gradual bends in them. So from my understanding removing the round flues will be next to impossible with a tile knocker type took since they are round and have some slights bends in them.

My question to you is if i had a 4.5 or 5" liner installed inside the old clay flues with a turbine cap would the draft be too little to operate the wood stoves?
They are medium to small size stoves with 6" exhaust. Given both stoves have an outside air exchange i am guessing this improves the draft and exhausts the smoke better than a regular stand alone wood stove would.
The flue for the upstairs wood stove is 23' tall and the down stairs one is 29' tall.
In the past both flues were never dirty even after a winter of burning 3-4 cords of wood (clean dry wood) so i am guessing prior to the flue being damaged they had a great draft.
Thank you in advance -Rob

 

[bholler]

a 5.5 might work not sure what stoves you have but it you have smoke coming out the outside of the chimney you obviously have really bad gaps in the liner and the chimney itself. I would have the structure evaluated before putting the money into a possibly undersized liner into a possibly compromised structure.

 

[smokedragon]

In my shopping a few stoves say right in the manual that they are approved to run off of a 5" flue (specifically inserts).

Drolet Escape 1800i, Century (forget the model) are both made by SBI. SBI will allow their smaller stoves to run on a 5" liner.

Check with the manufacturer of your stove.

If they say no, and you are unwilling to buy a new stove, try it anyway. I have seen a couple of really big homemade stoves (bigger than buck 91, BK king, etc) run on a 6" liner, and draw really well.

 

[BrotherBart]

Tell us what stoves you have and then we can start the conversation. I can't see them from here.

 

[rsr347]

Sorry guys, the main stove i use is a Vermont castings "defiant" model (23' of flue), and the smaller one (in the basement with the 29' of flue) is a vermont castings "aspen" model

 

[BrotherBart]

Measure the hole in the stove top inside the flue collar. Hard to say that the pipe should be larger than that no matter what the size of the flue collar. For an example I have a 3.5 cubic foot steel stove and the hole in the top of it is 5.5". That is the size of the liner I use in the 21' chimney.

 

[smokedragon]

But there are people successfully running a stove with a 6" flue collar on a 5.5" or 5" liner. Hopefully one of them will chime in.

 

[BrotherBart]

But there are people successfully running a stove with a 6" flue collar on a 5.5" or 5" liner. Hopefully one of them will chime in.

I did chime in. In the post above yours.

"For an example I have a 3.5 cubic foot steel stove and the hole in the top of it is 5.5". That is the size of the liner I use in the 21' chimney."