High valley liner size/installation questions

[brettdacosta]

See here (https://www.hearth.com/talk/threads/high-valley-insert.159624/) for back story...

I got a 6" liner and wrapped it with 1/2" insulation, ovalized the bottom 2 foot to fit through my 3 1/4" wide damper, pulled pretty substantially to get it down through the damper, enlarged from 6" to 8" to mate with the stove, and found the liner's flexibility limits. Now I need a 45° elbow to make the last connection.

Some questions. Should I use a 8" elbow directly to the stove, and then reduce to 6"? Or should I move the reducer to connect with the stove and then install the 6" elbow to it? Or does it make a difference.

I think I want the elbow connected directly to the stove, but I'm wondering what you guys opinions on that are.

See pictures for the setup and installation so far...

 

[bholler]

Well you should not have ovalized the liner you seriously reduced the volume of that liner and it may not work right. I dont see that it matters which size elbow you use I would probably use a 6" elbow though. Just so you have a little more room and it would be cheaper as well

 

[brettdacosta]

I appreciate your response, bholler.

I didn't want to cut the damper out, so it was the only option. The area is around 28in² for a 6in pipe. Best I can see (I'll throw a tape to it tonight) , it's probably still around 2.75" by 8.5". That's still over 23in² If you take 5% off for the radius of the oval (since it's not a perfect square), it's probably still 22in². I guess I don't count that as a "seriously reduced" volume. Maybe I'm wrong though.

I do realize, however, it isn't the ideal installation, but not everyone has a perfect chimney for installing a liner in. From what I hear the 22' height of the chimney and the insulation should really help with the draft. I guess I'm hoping those positives leave that short run of reduced area (an obvious con) a non-issue.

Could someone else provide some input, please?

 

[bholler]

I don't count that as a "seriously reduced" volume. Maybe I'm wrong though.

You also have to factor in the increased turbulence due to the pipe no longer being round. You actually have almost a 20% reduction in draft. That is pretty serious. I hope it works for you but it was not the right way to do it at all.

 

[bholler]

but to answer your question again it really makes no difference if you use a 6" or a 8" elbow other than the 6" will be cheaper and easier to work with

 

[brettdacosta]

What is the correct way to install it then? And why do I see so many people "ovalize" their pipe? I kind of thought that was standard?

 

[bholler]

What is the correct way to install it then?

Cut the damper frame and keep it round

And why do I see so many people "ovalize" their pipe?

Los of people also install inserts as slammers. Lots of people dont insulate their liners. Lots of people under size their liners ect ect. Just because lots of people do it doesn't mean it is right.

I kind of thought that was standard?

It is not standard. Yes many people even some pros do it but it is not the best or the right way to do it.

It may work just fine I don't know there are way to many variables involved for me to say one way or another but you have made it much harder to clan and you have handicapped your system with a pretty big restriction.
I hope it works out for you really but I want to be very clear so other people looking for advice on their install.