Looking for advice with yurt chimney

[rscottcush]

Hello all,

I live in a 30' diameter canvas yurt with a Woodstock Fireview as our sole heat source. It's an awesome stove that generally works great... after I clean the chimney. However, I seem to be getting creosote build-up in the chimney at a pretty fast rate. This is my first time living with a woodstove so not really sure what's normal, but I cleaned the chimney in mid-December, for example, and I think it's more than needs it again already after regular-but-not-super-heavy use for that month and a half. We were gone most of that time and had a yurtsitter who I suspect might not have been running the stove quite right, as it smelled pretty smoky inside when we got home, But apart from any operater error issues, I'm wondering if there are some tweaks I could make to the chimney system that would help. I get a little nervous when it smells like smoke inside that I'm slowly poisoning my family!

A month or two after cleaning the chimney I start to get increasing problems with smoke coming into the yurt when reloading the stove or starting a fire. The last couple days have been super windy and that seems to have increased the smoking issues. Apart from the general hassle of cleaning the chimney, it is extra annoying in a yurt because the structure doesn't hold heat very well - in winter by the time the stove is cool enough to clean, the yurt is freezing inside! We pretty much have the stove going non-stop from late fall to early spring. So anything I can do to extend the cleaning interval would be wonderful.

I'll attach a couple pictures, but basically, stovepipe comes out the back of the stove, 90's up, runs vertical a few feet, 90s out the wall into a T and then runs up 10 feet to cap. The two things I'm suspecting might be issues:

- Is the 10' main stack (plus the 3' of vertical single wall inside) enough height, given the two 90s and T in the system? If not, how much should I extend it?

- My interior pipes are connected a little off, such that the joints aren't totally tight since the angles aren't perfect 90s (this also causes the part of the 90 that connects to the stove to be angled slightly downhill away from the stove, and I have noticed some sooty discoloration on the outside of that 90). Wondering if I should just put furnace cement in the joints each time I put them back together after cleaning? Or worth it to reconfigure the set-up so that the angles are more perfect 90s?

My guess is that I just need to add more height to the chimney, but since that double walled ain't cheap, I thought I'd get some opinions before I try that. Any thoughts on the above, or anything else I might be missing would be greatly appreciated!

BTW, I am using well-seasoned dry wood, mostly doug fir from the property, and am confident that I'm operating the stove and catalytic combustor correctly.

Cheers,
Scott

 

[gthomas785]

How dry is your wood?

 

[rscottcush]

It should be plenty dry. I don’t have a moisture meter, but it was thoroughly dried all last summer and stacked in a well ventilated woodshed in the fall.

 

[begreen]

What species wood are you burning? Maple, fruit tree, and alder will need more than a summer of drying. Doug fir if split in March and placed in a good, sunny and well-ventilated location can be ready by November.

As for the stove setup, it should have been directly vented straight out instead of having three 90º turns in the smoke path. This is slowing down and cooling down the flue gases which will increase creosote buildup in the cold outdoor chimney. In the least the stovepipe should be double-wall. One option would be to pull the stove further into the room and come off the flue collar with a 45º elbow pointing upward connecting to another 45 elbow at the chimney thimble. Doing this will elimate one 90º turn. This should be done in double-wall stovepipe.

What is being used for chimney pipe? It usually isn't black. Is this stainless class A pipe that has been painted? Is the current stovepipe at least 18" away from any wood?

 

[rscottcush]

Thanks for the response @begreen . I’m burning Doug fir that was seasoned all summer, plus a little bit of very dry oak at night. We have hot dry windy summers here and it was stacked in single rows so pretty sure it’s plenty dry.

I know it would have been better to send it straight out the wall and avoid the two 90s, but I already had the hole in the wall up higher from our previous stove (that proved to be too small) and didn’t want to reconfigure the whole thing and cut another hole in the wall. The black pipe inside the yurt is single wall stovepipe. Outside I have double wall stainless pipe that was painted black. Are you saying using double wall for the interior run will help with the creosote build up and/or the draft?

I don’t think I have enough room to get away with the double 45 move. I’d have to move to stove too far forward.
Would adding another 18” or even 3’ to the exterior stack help?

thanks,

 

[peakbagger]

Looks like you may need to do what my neighbor did on an OWB. His stack was too low and was skunking out the neighborhood. He tried adding length unsupported but it still was no tall enough. He ended up installing a steel flagpole next to his stack and supporting the stack off the flagpole. He still has issues on occasion but mostly on days when its cloudy with low clouds.

 

[SpaceBus]

If the joint coming out of the stove is angled down then you need to fix this ASAP. In fact the pipe should angle up if at all. Correcting that issue will help with smoke spilling. If you are committed to keeping the class A as is then maybe double wall inside will help. If you are spending money I would just make the stove connect directly to the class A out the back, but that would really limit stove options in the future.

Your wood may still have too much moisture. The Yurt sitter could also have operated the stove in a way that built up creosote. It would not take much.

I accidentally filled my cookstove with creosote on my first season. With two weeks of closing the bypass too soon I clogged up the stove passages and smoked out the house.