Temperature in between liner and chimney

[Ctwoodtick]

I was curious what may be the temp between my ss liner and the terra cotta liner in my masonry chimney when stove is in use. The specifics are chimney is about 16 or 17 feet tall. Uninsulated ss flex liner. No block off plate at bottom. Top plate on terra cotta up above.

 

[brenndatomu]

During normal use, maybe 200*, During an overfire, maybe 500*, during a "chimney fire" inside the liner, maybe 1000*? Hard to say for sure...

 

[bholler]

In a chimney fore it can easily get way over 1000. The other numbers listed above sound right to me. That is why it should be insulated

 

[Nick Mystic]

I think the OP might have been referring to the air temperature between the outside of the ss flex liner and the clay tile liner, as opposed to the temperature inside the ss flex liner. If so, I can say that my upstairs set up is similar to his, except I have an insulated block off plate and stuffed insulation up top for the uppermost five feet (the distance the masonry chimney sticks up above my roof). I've never measured the inside temperature of the masonry liner since there is no access point to do so. However, I have shot the brick chimney with my IR thermometer, which is located in the center of the house, and get readings in the triple digits down low and in the upper 80s and 90s near the inside top. I intentionally installed my flex liner with no insulation for this reason - extra heating inside the house. My chimney has over 6000 bricks in it and of course beneath the brick is the cinder block structure. This is a huge heat sink that slowly gives off heat long after the stove cools down, much like a masonry heater.

 

[bholler]

I think the OP might have been referring to the air temperature between the outside of the ss flex liner and the clay tile liner

Yes I know that and those are the temperatures I have given

I intentionally installed my flex liner with no insulation for this reason - extra heating inside the house. My chimney has over 6000 bricks in it and of course beneath the brick is the cinder block structure. This is a huge heat sink that slowly gives off heat long after the stove cools down, much like a masonry heater.

Yes but by doing so you for one did not install the liner per its Ul listing and due to that are not to code and in cases where the chimney does not meet the required clearance to combustibles it could be a fire hazard. You are also loosing heat in the stack which can lead to more buildup.

 

[Nick Mystic]

bholler, what code do you think I'm violating? My ss flex liner sits inside a 13" x 18" clay tile flue that has a cinder block chimney clad in brick that is 8' x 4' in size. There is no combustible material anywhere near the clay tile liner, let alone within two inches of it. Also, I'm not familiar with the UL listing you mentioned that says all ss flex liners must be insulated. I've always heard that only flex liners that were inside damaged clay tile liners needed insulation.

I burned about four cords of wood this past winter and when I inspected my liner recently there was barely a dusting of soot inside it, so the heat I'm losing though the stack, that helps heat my house with my "center of the house" chimney, doesn't appear be producing any creosote build up.

 

[bholler]

bholler, what code do you think I'm violating?

You are required by code to install any listed product in accordance with its listing. Ul listed liners are tested for use with wood with insulation there for to meet code you have to install them that way.

There is no combustible material anywhere near the clay tile liner, let alone within two inches of it.

You need the 2" from the outside of the masonry structure not the clay liner.

Also, I'm not familiar with the UL listing you mentioned that says all ss flex liners must be insulated.

They are tested and listed with insulation for use with wood so to meet the listing they need to be installed that way.

I've always heard that only flex liners that were inside damaged clay tile liners needed insulation.

There is nothing in any code or listing that even mentions the condition or even existence of clay liners when it comes to requirements when installing a liner.

I burned about four cords of wood this past winter and when I inspected my liner recently there was barely a dusting of soot inside it, so the heat I'm losing though the stack, that helps heat my house with my "center of the house" chimney, doesn't appear be producing any creosote build up.

And I never said it would but by loosing more heat from the stack you are increasing the risk of buildup.

 

[bholler]

And by the way I dont take issue with the way you installed your own liner. You did it in your house so you are assuming the risks and liability of doing it that way. But I feel I have to make it very clear that there several different potential problems of doing it that way to those who are coming here for advice.

 

[Nick Mystic]

This is a real eye opener for me. I bought my Olympia ss flex liner from the stove company where I bought my Jotul F600 stove. They have been in business for quite some years in NC and they never mentioned any code requirement that the liner be insulated in my installation. There must be quite a lot of participants here at our forum operating under the same assumption as me since it is rather common for members talking about installing their ss flex liner without insulation.

 

[bholler]

This is a real eye opener for me. I bought my Olympia ss flex liner from the stove company where I bought my Jotul F600 stove. They have been in business for quite some years in NC and they never mentioned any code requirement that the liner be insulated in my installation. There must be quite a lot of participants here at our forum operating under the same assumption as me since it is rather common for members talking about installing their ss flex liner without insulation.

Yes it is common. I have even had guys argue I was wrong after providing them with the codes showing them I was right. And I install allot of olympia liners and I know their instructions say that they need to be insulated to maintain the ul listing.

 

[Nick Mystic]

I'm starting to think you and I are using a different set of standards. I'm talking about a masonry chimney that meets the NFPA 211 standard for masonry chimneys. It sounds like you are talking about chimneys that don't meet this standard. I just went back and read the requirements for installing a ss flex liner in a masonry chimney that meets the NFPA 211 standard for masonry chimneys and it said that no insulation was required. Granted, for maximum safety one should assume their chimney does not meet this standard and error on the side of caution and insulate the liner. However, when the chimney does meet this standard then it is considered acceptable to install the flex liner without insulation. I'm not trying to belabor this point, but I know a great many of us here at the forum have safety high on our list of concerns as we burn and I don't want everyone who reads this post to think they are breaking a building code if their liner is installed in a masonry chimney meeting the NFPA 211 standard, but they didn't insulate it.

 

[bholler]

I'm starting to think you and I are using a different set of standards. I'm talking about a masonry chimney that meets the NFPA 211 standard for masonry chimneys. It sounds like you are talking about chimneys that don't meet this standard. I just went back and read the requirements for installing a ss flex liner in a masonry chimney that meets the NFPA 211 standard for masonry chimneys and it said that no insulation was required. Granted, for maximum safety one should assume their chimney does not meet this standard and error on the side of caution and insulate the liner. However, when the chimney does meet this standard then it is considered acceptable to install the flex liner without insulation. I'm not trying to belabor this point, but I know a great many of us here at the forum have safety high on our list of concerns as we burn and I don't want everyone who reads this post to think they are breaking a building code if their liner is installed in a masonry chimney meeting the NFPA 211 standard, but they didn't insulate it.

You are correct if your chimney has the required clearances to combustibles which in your case would mean that there was no combustible material with in 2" of the masonry structure you would not be required to insulate by that code requirement which is R1001.15 But in R1003.11 You are required to install any lining material in accordance with its listing. And on this page (broken link removed) Olympia clearly says you need to insulate to maintain the listing when their liners are used with wood. And to my knowledge there are no stainless liners listed to UL-1777 that do not require insulation when installed for wood. I guess there could be some I do not know of but I know your requires it.

 

[Nick Mystic]

Thanks for the clarification.

 

[bholler]

Thanks for the clarification.

No problem

 

[Texas123]

I am having my old 8 inch liner removed and new 6 inch stainless steel will be installed when the Jotul 500 Oslo arrives.

If the installers arrive and I see single wall liner should I send them back to the store?

I was assured by the salesmen at Leonard's Stone and Fireplace their installers do everything to code and if they had not they would not have been in business for over 30 years.

 

[bholler]

If the installers arrive and I see single wall liner should I send them back to the store?

No there is nothing wrong with single wall liner. The large majority of liners installed are single wall. Are they insulating the liner? Did they do a full inspection to verify clearances to combustibles?

 

[brenndatomu]

I am having my old 8 inch liner removed and new 6 inch stainless steel will be installed when the Jotul 500 Oslo arrives.

If the installers arrive and I see single wall liner should I send them back to the store?

I was assured by the salesmen at Leonard's Stone and Fireplace their installers do everything to code and if they had not they would not have been in business for over 30 years.

Single wall is OK, but it should be insulated...

 

[Ctwoodtick]

During normal use, maybe 200*, During an overfire, maybe 500*, during a "chimney fire" inside the liner, maybe 1000*? Hard to say for sure...

What do you all figure these numbers would be if the stainless liner was INSULATED?

 

[brenndatomu]

What do you all figure these numbers would be if the stainless liner was INSULATED?

MUCH less on the outside

 

[bholler]

What do you all figure these numbers would be if the stainless liner was INSULATED?

I think the 200 number is high I would say that is more like 100 to 150. But I think the rest of the numbers are pretty good.

 

[brenndatomu]

I think the 200 number is high I would say that is more like 100 to 150. But I think the rest of the numbers are pretty good.

You are talking after insulation? I would agree with 100* on the outside after insulation...

 

[bholler]

You are talking after insulation? I would agree with 100* on the outside after insulation...

Yes and in an overfire you could easily recede 1000 so I don't think 500 outside is out of the question. And a chimney fire can be over 2000