Chimney liner Question ?????????

[02809bristol]

I presently own a ZC wood fireplace ( Heat N Glo ) . I put a deposit down on a Harman 52i insert. After shopping for a month and talking to different dealers I was told I could use my existing ZC firebox as the ZC cabinet for the new Harman 52i.

I was then told that I can use the existing double walled pipe( air cooled ) 10 inch outside and 8 inch inside as the chase to the top.

I called online dealers today to get pricing on a liner kit , I was told that I could use SS liner , BUT IT WILL NOT BE UL listed , the manufacturer does NOT test for my application ! So if anything were to happen ????? My Insurance Co wouldn't cover ???

Are there any chimney guys out there who could shed some light ? I can't see this pellet 4" liner getting any hotter than a good full blazing fire.

I thought this would be a simple liner install, helped a co worker do his liner and it only took 2 hours !

 

[batchman]

As I understand it the problem is not the heat in the exhaust, it's the lack of heat. Problem being keeping the exhaust above the condensation temperature so that creosote doesn't form. An 8" liner is probably too big, I'm running my 60k btu stove up a tall 6" and would not be surprised to find I need to re-line when I open 'er up to check at 1 ton mark.

HTH,
- Jeff

 

[RhodyPelletRook]

Batchman, excellent advice. Spot on.

 

[Mt Bob]

You want to run a liner inside another liner.It is done all the time,with the proper materials(they are availible)But the final say is your local inspector,most see this as a good install.

 

[chimneylinerjames]

A chimney liner installed inside an existing chimney is UL listed. You are right about the heat, this will stay much cooler than having an open fire place. But you should have insulation on the liner as the other posted said for the lack of heat. If the liner cools down too much, you will have major creosote build-up.

 

[02809bristol]

A chimney liner installed inside an existing chimney is UL listed. You are right about the heat, this will stay much cooler than having an open fire place. But you should have insulation on the liner as the other posted said for the lack of heat. If the liner cools down too much, you will have major creosote build-up.

So why are they saying it won't be UL rated ? Better to go with 316 or 304 gauge ?

 

[chimneylinerjames]

I am not sure what company you spoke to or why they said that.

316 and 304 are not gauges of metal. They are grades of stainless steel, specific alloy mixtures. 304 is good for wood and only wood. 316 is a metal that can handle multiple fuels, its alloys can withstand the acids from a gas or oil appliance.

 

[p962man]

This is a very grey area in the world of hearth installations using existing ZC fireplace systems. I can't think of any ZC fireplace that specifies a UL listing for the retrofit of inserts, mainly because it would cost the manufacturer money to do so and they are worried about building a product so inserts can be installed in them 15 years later. The key is that your fireplace and chimney is designed as a system- so in terms of UL listing, when your existing fireplace was going through testing, it was being tested with the air-cooled chimney designed to be installed with the fireplace. In a lot of cases, the air that is being used to insulate the chimney installed with your fireplace is also being used to insulate the cabinet of your ZC box to maintain required clearances. The existing cap on your chimney should be designed to exchange the air being used to insulate the "system", as well as to safely expel the flue gases from the firebox. Technically speaking, you can reline the chimney for an insert as long as these air channels are not compromised and can operate as they normally would. Duravent just released a liner system that is designed specifically for retrofit in factory built chimneys which would include the air cooled chimney found in your situation.

A more expensive, but more black and white solution to this problem would be to run pellet vent, listed to be used with the unit you are installing, inside your existing flue. In this case, you are not relying on the existing chimney to provide any function in maintaining clearances, it is just a conduit for a separate chimney system to get to the roof. You are guaranteed to meet the vertical clearance for the PL vent which in most cases is 1", worst case 3". At the end of the day, insurance companies involved with settling a major loss situation are good at finding technicalities to be able to pass blame and deny coverage, even if it is not related to the cause of the loss. My advice would be to get your local building codes official involved and be forthright with your insurance company about what you are planning on doing so everyone is on the same page, and make sure you run and maintain your unit properly and according to manufacturer specifications to minimize the risk of fire hazards.

 

[02809bristol]

This is a very grey area in the world of hearth installations using existing ZC fireplace systems. I can't think of any ZC fireplace that specifies a UL listing for the retrofit of inserts, mainly because it would cost the manufacturer money to do so and they are worried about building a product so inserts can be installed in them 15 years later. The key is that your fireplace and chimney is designed as a system- so in terms of UL listing, when your existing fireplace was going through testing, it was being tested with the air-cooled chimney designed to be installed with the fireplace. In a lot of cases, the air that is being used to insulate the chimney installed with your fireplace is also being used to insulate the cabinet of your ZC box to maintain required clearances. The existing cap on your chimney should be designed to exchange the air being used to insulate the "system", as well as to safely expel the flue gases from the firebox. Technically speaking, you can reline the chimney for an insert as long as these air channels are not compromised and can operate as they normally would. Duravent just released a liner system that is designed specifically for retrofit in factory built chimneys which would include the air cooled chimney found in your situation.

A more expensive, but more black and white solution to this problem would be to run pellet vent, listed to be used with the unit you are installing, inside your existing flue. In this case, you are not relying on the existing chimney to provide any function in maintaining clearances, it is just a conduit for a separate chimney system to get to the roof. You are guaranteed to meet the vertical clearance for the PL vent which in most cases is 1", worst case 3". At the end of the day, insurance companies involved with settling a major loss situation are good at finding technicalities to be able to pass blame and deny coverage, even if it is not related to the cause of the loss. My advice would be to get your local building codes official involved and be forthright with your insurance company about what you are planning on doing so everyone is on the same page, and make sure you run and maintain your unit properly and according to manufacturer specifications to minimize the risk of fire hazards.

Thanks to everyone's input
I was wondering what's Duravents model name for new pipe?