Very tricky install to offset thimble

[tomzpc]

We are looking at getting an Avalon Olympic free standing stove for our home in NY. Here's a link to my thread asking about the Olympic and if it suits our needs:
https://www.hearth.com/talk/threads/avalon-olympic-too-much-stove-for-us.93878/

Now is where things get real tricky. I've attached a photo of the hearth with some dimensions. As you can see the thimble/crock is not centered on the hearth. The plan right now is to 45 directly off the top stove collar into an adjustable slider and into a T which will direct the pipe through the crock and into the chimney, all with 6" double wall. Does this sound doable? Original install years ago when we bought house had old VC resolute with 45 off stove top, one fixed run up to thimble and then a 90 to a thimble adaptor. We had replaced this with a pellet stove years ago but now want to go back to a wood stove.

Had the exterior block chimney(terra cotta lined) inspected and was advised to install heavy duty (smoother walled) 6" liner down chimney to a T at the thimble. Liner would be insulated with pour-in vermiculite? mix since flue size is only 6 1/2" x 10 3/4", so no room for a wrapped liner. Top of chimney is 18' above thimble so hopefully I'll get enough draft. So with the above plans there would be a 6" pipe running through the thimble to connect from the inside Tee to the liner Tee.

Does the above make sense or does anyone have other ideas?

Because of the fixed thimble and fixed 45 degree angle, the height of the stove collar/45 connection will dictate "where" the stove sits on the hearth. In other words, the stove won't necessarily be centered and likely won't be. Assuming a 45 double wall can be attached directly to the stove collar, can anyone tell me what the distance up from top stove collar to centerline of the 6" pipe would be? With that dimension and stove height I can determine stove location and have it marked on the hearth prior to install. Again, assuming this plan sounds reasonable.

Thanks!

 

[trog04]

Tomzpc,
I think I understand your issues. I had to use a 45* to offset my install, and it really wasnt a big deal. I used DVL from Duratech, which is double wall stovepipe. I looked in their catalog, and it looks like all of their elbows are adjustable.

Here could be a plan: Put the stove adapter on the stove and connect the 45* elbow on that. I would then use an adjustable section of stovepipe from the elbow up to where the thimble is located. With the adjustable elbows, you can place the stove where you want, then move/adjust the individual sections of the elbow to get the angle right. Once the angle and length is right, place a 90* elbow from the adjustable section directly into the thimble/chimney section.

Getting the right distances for me was just a little bit of trail and error, but it really went together nicely. To get the exact distances, I would need a few more measurements, such as the dimensions of the stove and collar, how high it is off the floor, if you use and exact 45*, or an adjustable elbow would change the distances. If you use a strict 45*, the distance horizontally from the hole would be the same as the distance from the top of the stove collar on a vertical line extending to the centerline of the hole.

I hope this helps and gives you at least a little direction.

Edit: Here's a really crappy drawing. If you use the 45* elbow, distance A will equal distance B, (where they intersect, not the whole line) if that makes sense.

 

[DexterDay]

Use an adjustable length section of pipe??Thats what a few people have done?

What brand of venting are you using?

 

[tomzpc]

Haven't decided on any particular brand of venting yet. Trog, I don't think anyone makes a double wall elbow that is adjustable. Not sure how that would even be possible? Even with the adjustable/slip straight run I think the stove location will pretty much be set based on 45 degrees from the thimble and the height of the stove.

Can a 45 double wall connect right to the top stove collar or is an adaptor needed there?

Thanks guys.

 

[trog04]

http://www.duravent.com/docs/product/dvl_durablack_L820_2012-sept_w.pdf
Here's what I'm using, DVL from DuraVent. They have telescoping sections of pipe up to 60" and it says the elbow angles are adjustable. As far as the elbow fitting directly on the stove collar, I believe most stovepipe manufacturers have an adapter that makes the transition from the stove to the stovepipe.

Granted, I haven't been able to fire up the stove yet, waiting on a final inspection from the county, but I have been VERY pleased at how easy the whole system went together.

 

[tomzpc]

http://www.duravent.com/docs/product/dvl_durablack_L820_2012-sept_w.pdf
Here's what I'm using, DVL from DuraVent. They have telescoping sections of pipe up to 60" and it says the elbow angles are adjustable. As far as the elbow fitting directly on the stove collar, I believe most stovepipe manufacturers have an adapter that makes the transition from the stove to the stovepipe.

Granted, I haven't been able to fire up the stove yet, waiting on a final inspection from the county, but I have been VERY pleased at how easy the whole system went together.

Thanks Trog. Do you have a picture of your install? Just curious.

I think they say adjustable in their literature but I have a hunch that the elbows aren't. I've already read on here from a few people that they couldn't locate adjustable double wall pipes. Guess I'll shoot an email off to Duravent and ask them.

 

[Dakotas Dad]

Why not use single wall?

 

[tomzpc]

Why not use single wall?

Good question. I just thought that double wall is the norm nowadays and that there is much less chance of smoke leaking from the joints, particularly since I don't have an "ideal" draft situation.

I really don't know what to do at this point. Hopefully I'll get more feedback on this. The one shop recommended heavy duty SS liner with vermiculite insulation poured in, and that the pipe going through the thimble/crock be double wrapped in some kind of insulation. First shop said just to regular flex SS liner and no insulation needed. They said they have never insulated their liners and never had any issues. Was I right to walk away from those guys?

Do you guys think that I should use a 90 elbow or put a Tee to enter the thimble to make cleaning easier? Would a Tee look okay there or would it look big, ugly and out of place? LOL. The Tee was recommended by the guy who recommended the insulated liner. So there would be a Tee on both sides of the crock. One on the inside for cleaning and one in the chimney for the liner connection.

Keep the ideas and thoughts coming please!

 

[OhioBurner©]

Single wall is cheap, I'd just try that out if you can't get double wall adjustable elbows. A lot of folks including myself just use single wall, and my venting isnt that great either (uninsulated 15' single wall liner).

Assuming for a sec you are stuck with non-adjustable elbows, you could raise the stove, or lower (if it has different leg option). Raising might not look the best, but you could probably make it blend in if you had the same bricks and made litte raised pads under the legs or another mini-hearth under the whole stove raised up higher.

As for the tee in the thimble I don't think I've ever seen that done before. A 90 elbow would have a better gradual transition too. I've not used double wall is it that big of a pain to disconnect it for cleaning?