Question about a Chimney Liner

[mik_kane]

1.Why does a chimney liner have to be insulated and regular vent pipe does not need insulation?

2.When installing a chimney liner for a pellet stove, does the liner have to be insulated like a liner for a wood stove?

3.Can you install a solid vent pipe in a chimney and connect a flex pipe to go around the flue opening to the stove and does the flex pipe need to be insulated?

4. If you use a solid vent pipe in a chimney how do you support it? Do they make anything for that application?

Thanks

 

[webbie]

1. Not sure what you mean by "solid vent", but if you mean rigid ss pipe it does have to be insulated to bring a chimney up to modern code (in most cases...unless the chimney is already fine).

2. I don't think it has to be insulated - probably because it is positive pressure and small (fan forced, not relying on natural draft).

3. Lots of installations use rigid and then transition to flex to go through the same and down to the stove. IMHO, in most cases, it's OK to leave some of it in that area uninsulated where it's impossible to insulated it. But it should be wrapped if it touched the masonry on the front of the fireplace, etc. because heat can really transfer through there. In such a cast, it may not be wrapped from slightly above the damper down to the stove connection.

4. Most liners are riveted and screwed together and held up by the top plate on the chimney. In other words, most of the weight is hung.

 

[mik_kane]

Not sure what you mean by "solid vent", but if you mean rigid ss pipe it does have to be insulated to bring a chimney up to modern code (in most cases...unless the chimney is already fine).

I should of said regular vent pipe. I will change it. Thanks for your replies

 

[AJ9]

I had some of the same questions. Someone already said the liner is hung by the top plate. I have a lot of pipe length and had called some of the manufacturers, whom said the clamp at the top can support the full 30 or so ft of pipe. Seemed like a lot to me.

Researched insulating as well. I'm debating ridgid pipe, which is really hard to install in my tall chimney, or smooth wall flex pipe. There doesn't seem to be a straight answer on insulation. Seems you don't need it, but are better off with it basically. If you have the money and want some insurance or have a really long vent near the limit of your pellet stoves output, then it is probably a good idea from what I have been told.