ss chimney liner questions

[qwerty]

I'm trying to make a decision about a wood burning fireplace insert and the dealer/installer I want to go with. One installer mentioned something in his estimate that others did not. We are going to go with a stainless steel pipe running up the interior of a brick chimney. He suggested the that liner be surrounded with insulating material in order to keep it warm. The benefit is supposed to be that it will draft better and be cleaner inside. Is this legit?

Also, if a unit calls for either a 6" or 8" pipe, which is better to go with, or does it make no difference?

Thanks for your help.

 

[philaphire]

From what I have learned, liner insulation is a good idea when the chimney is on an exterior wall and is a requirement when the current chimney is either unlined (no terra cotta tiles) or in bad shape (damaged or missing terra cotta tiles). Thus insulation does 2 things. 1. It helps keep the pipe warm which means better draft/less creosote and 2. in the event of a chimney fire helps contain it inside the pipe. Many on this forum give testimony to insulating their liner having run with and without insulation.

I'm not sure of any advantage/disadvantage to 6" vs 8" except just about every new stove on the market is 6" if that says/means anything.

 

[Metal]

I would go with 6" in case you ever change stoves it gives you more options. You can insulate the liner be either wrapping it with insulation prior to inserting it, or by filling the space with a vermiculite/concrete substance after inserting it. It is better than uninsulated for draft purposes, but not always needed if draft is not an issue or it is in an interior chimney.

 

[jtp10181]

A lot of liners out there only meet UL 1777 with the insulation. FYI. So unless the masonry chimney is Terra cotta lined, in very good shape, and passes a Level II (I think that's the right one?) inspection it should be insulated.

 

[jmd425]

This all depends on the details...chimney type size of flue length lined or unlined etc..

 

[webbie]

What is the model you are installing? What is the flue collar size? In general, that is the best size liner to use. Exception might be something like a VC encore that is really an 8, but listed to work with a 6. I would install an 8 in that case, since it allows the stove to be used with front doors open and is less likely to smoke out front and top, etc.

 

[qwerty]

I have not made a final decision on a model. However, the model I am considering which prompted the question was the Lennox/Country Stoves C260 Legacy.

Your post gave me a thought, and I went back and looked at the brochure. I guess that this insert might fall into the same category as the VC you mentioned, because the fine print makes reference to requiring a "reducer" to work with a 6" pipe.

 

[webbie]

I looked up the manual on that unit - it is about as clear as MUD.......

If you read the actual words, it seems to say that you can use a 6" connector pipe to an 8" class A chimney.....or an 8" connector pipe to same.....then it says " see instructions" although you are already looking at them!

This is some kind of black magic or voodoo. I would suggest talking to a long time country dealer....someone who confidently knows why they are beating around the bush in this manual. I would think they would make it clear such as "a short 6" chimney may smoke, so use 8" if less than X, etc." - but instead they give no reason for any of the specs.....strange.