Is insulated liner necessary?

[Niro]

We had a lopi insert installed last year and it seems to work well. When the installer came I asked about insulation on the liner. He said this is how we normally install it. It's a standard 25ft single story chimney.

I'm in the market for a second insert in a part of the house that is 2 stories so the height is much greater. What are the benefits of insulation vs non?

 

[bholler]

We had a lopi insert installed last year and it seems to work well. When the installer came I asked about insulation on the liner. He said this is how we normally install it. It's a standard 25ft single story chimney.

I'm in the market for a second insert in a part of the house that is 2 stories so the height is much greater. What are the benefits of insulation vs non?

Safety and performance are the benefits.

Does your chimney have the required clearance from the outside of the masonry structure to combustible materials?

 

[Niro]

The chimney extends approx 10 ft above the roofline. Its likely is not a safety issue in my case as prior to insert it was used a chimney for open fireplace.

How does the performance increase if an insulated liner was installed vs non insulated?

 

[bholler]

The chimney extends approx 10 ft above the roofline. Its likely is not a safety issue in my case as prior to insert it was used a chimney for open fireplace.

How does the performance increase if an insulated liner was installed vs non insulated?

Height above the roof doesn't matter when it comes to insulation. The chimney needs clearance from the outside of the masonry structure to combustible materials. 1" for an external chimney or 2" for an internal one. Without that gap enough heat can transfer through to cause pyrolysis and a potential fire risk.

Performance will increase because the liner will heat up faster and lose less heat

 

[brenndatomu]

Its likely is not a safety issue in my case as prior to insert it was used a chimney for open fireplace.

Just because there was no issue so far, is not a guarantee that it was built properly...I'm sure bholler can show us lots of pics of charred framing from some really old houses that just hadn't burnt, yet...and plenty that did too.
For me, it wasn't a decision, that extra $400 (or whatever it was) for the insulation kit was some cheap insurance that helps me and my family sleep better at night, all winter long. (we burn 24/7)

 

[begreen]

The liner is infrastructure. Do it as safely and highest quality as possible so that you are not revisiting it will issues.

 

[Niro]

Agreed not sure what was involved in the first insert. But I will make sure the second is insulated, sounds like no real downside but extra cost.

 

[Corey]

Extra cost for sure, but that could pay back if you're buying your wood. There are three main places heat gets out of your stove

- It comes into the room as 'useful' heat.
- It comes out of the stove pipe walls - but unless you have some special cases like the pipe exposed in your room, or central chimney still warming the house, most of this heat is lost to the outdoors.
- It comes out the top of the stove pipe which generates draft to make the whole system work.

So the insulation will stop some of the waste heat out the flue meaning you can burn a bit lower fire and put the same heat in the room and same heat up the flue to drive draft.

 

[Niro]

Thanks that makes sense. I'll insist on insulation.

 

[mellow]

How tall will this be? You mentioned your first one was 25ft and this second one will be more. I am wondering if you will have overdraft issues.

 

[Niro]

How tall will this be? You mentioned your first one was 25ft and this second one will be more. I am wondering if you will have overdraft issues.

It's at least 50 ft I think. It would need to stretch past the second floor and clear the peak of the attic space. So alot taller than the first. No second story on that side of the house.

So if the height causes overdraft issues what does that do to efficiency I assume reduce it as more air is pulled through?

What are some solutions?

 

[bholler]

It's at least 50 ft I think. It would need to stretch past the second floor and clear the peak of the attic space. So alot taller than the first. No second story on that side of the house.

So if the height causes overdraft issues what does that do to efficiency I assume reduce it as more air is pulled through?

What are some solutions?

50'????

 

[bholler]

If it really is 50' I doubt you will get that draft under control

 

[begreen]

Agreed. 50 ft. is double the normal 2 story chimney height. This spells draft issues.

 

[Niro]

I'll take a measurement.

 

[begreen]

Anything above 30 ft has the potential for draft issues.

 

[brenndatomu]

50' will suck up nearby small animals when reloading!

 

[stoveliker]

Lol. At least there won't be smoke roll-out.
You may have yourself a good smelter though. If you like metal working, this might be hot enough...

I was already surprised by the 30 ft for single story.
I have 27' from my basement stove, past the first story, past and above the second story.

 

[Niro]

Ok ok ....15ft on the first one and the second potential one is 35-38ft. Hard to get an exact measurement but I confident in those numbers.

So is that too much draft? I'm considering either Blaze King Sirocco , regency ci 2700 or Osburn Matrix .

 

[bholler]

Ok ok ....15ft on the first one and the second potential one is 35-38ft. Hard to get an exact measurement but I confident in those numbers.

So is that too much draft? I'm considering either Blaze King Sirocco , regency ci 2700 or Osburn Matrix .

Yes 35'+ is absolutely going to give you too much draft

 

[Niro]

Yes 35'+ is absolutely going to give you to

What can I do to combat the draft?

 

[bholler]

What can I do to combat the draft?

The most effective way is with an inline damper

 

[stoveliker]

Or two. (for 35' chimneys...)

 

[Niro]

Or two. (for 35' chimneys...)

It this something the install can do. How does that work is it in a permanent position? or would it need to adjusted from time to time.

 

[stoveliker]

It's a simple flapper (metal plate) mounted on a rod that sticks through the flue pipe with a handle on the outside so you can rotate it (and thus tune how much blockage you put in the pipe to decrease draft). It would need adjustment from time to time depending on the weather mostly.

What is the key damper for?

Ok, so been going pretty good with my new Oslo...can't really complain much. There are some nights I don't seem to get good secondary action, but I"m learning little things about stacking the wood in the box and such so all in all I think I'm having a great year so far for a new burner-but it is...

www.hearth.com