Would I experience any draft issues related to an 8" flue venting a Jotul Oslo? The chimney has no bends and is 22' total length: 8' of double wall uninsulated from stove to ceiling and remaining is metabestos from second floor to terminus at 2' above roof peak. Chimney is dead centered in house. Is the 6" specification for the flue a minimum or the ideal? Thanks
Oversized flue for Jotul Oslo
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"Should" implies a level of risk that might not be advisable given the investment in the chimney?
XmasTreefarmer
Feeling the Heat
I think you will be fine. I Want to be careful with my advice - I've only burned my Oslo a bit in Spring and now a few times this Fall - no problems so far and the coldest it's been has been around 40 outside and the draft will only improve as it gets colder.
I vent from the top and then have a 90 where I connect to my masonry chimney which has an 8" flue. Total length from top of stove to top of chimney is about 16' if memory serves.
If you check your Oslo manual you will see that 8" is well below the max that they suggest.
I vent from the top and then have a 90 where I connect to my masonry chimney which has an 8" flue. Total length from top of stove to top of chimney is about 16' if memory serves.
If you check your Oslo manual you will see that 8" is well below the max that they suggest.
If this was pre-existing and in good shape would run with it if this were my house. Connect the stove with the top vent. The risk of build up is low with an interior chimney as long as the stove is burning fully seasoned wood and run properly.
XmasTreefarmer
Feeling the Heat
I was out of town when I replied to your post, so didn't have easy access to an owner's manual.
For the Oslo, Jotul says that you can go up to 3 times the cross-sectional area if the masonry chimney is not exposed below the roof line and 2 times the cross-sectional area if the masonry chimney is exposed below the roof line. That's for masonry which is what I have and mine is not exposed, so I have a lot of cushion as you'll see below ...
So, the 6" outlet on the stove is approx. 26 sq in. An 8" flue is approx 50 sq in.
I just double checked your post and see that you don't have masonry - for metabestos it says you can go to 3 times the cross-sectional area. So you are OK.
I also checked and my "chimney height" is around 22' - that's from the top of the stove to the top of the chimney. I have one 90 degree in the stove pipe where I go into the chimney, so if I subtract 2 - 3 feet for that, my effective chimney is around 19'. Minimum that Jotul recommends is 15'.
Hope that helps. I really like my Oslo and if you are interested in getting one, I do think it will work in your chimney. Wouldn't hurt to run it past a dealer.
For the Oslo, Jotul says that you can go up to 3 times the cross-sectional area if the masonry chimney is not exposed below the roof line and 2 times the cross-sectional area if the masonry chimney is exposed below the roof line. That's for masonry which is what I have and mine is not exposed, so I have a lot of cushion as you'll see below ...
So, the 6" outlet on the stove is approx. 26 sq in. An 8" flue is approx 50 sq in.
I just double checked your post and see that you don't have masonry - for metabestos it says you can go to 3 times the cross-sectional area. So you are OK.
I also checked and my "chimney height" is around 22' - that's from the top of the stove to the top of the chimney. I have one 90 degree in the stove pipe where I go into the chimney, so if I subtract 2 - 3 feet for that, my effective chimney is around 19'. Minimum that Jotul recommends is 15'.
Hope that helps. I really like my Oslo and if you are interested in getting one, I do think it will work in your chimney. Wouldn't hurt to run it past a dealer.
jetsam
Minister of Fire
Stoves that require 8" venting tend to be larger stoves. I'd personally take advantage of the 8" liner and shop for a big honking stove.
