Normal i think not

[etiger2007]

so i read a thread awhile ago and mello used a infrared thermo on the outside of his chimney, cant remember his readings but it was 28 outside today and i thought i would check my chimney on the out side , so i hit it with the infrared and my chimney on the outside read 60 degrees on the outside, readings were 30 to 60 degrees, my insert is wrapped in Roxul and also surounded by a steel heatalator steel box, what else can i do to keep the heat contained to the house and not seep through the chimney ? Gotta be losing a ton of heat right?

 

[bholler]

Do you have an insulated block off plate and an insulated liner? If so i dont know of allot more that you can do

 

[jatoxico]

What height are you taking reading? If it's at stove height and therefore coming from the stove then a layer of cement board or metal might do the trick. If you're reading higher like the level of the damper or smoke shelf then it must be coming from the liner and maybe you stuff more insulation up there?

Assuming you have a block of plate already?

 

[etiger2007]

I have roxul stuffed in the smoke shelf but no steel block off plate , i would say my reading of 60 degrees would be just above the insert

 

[jatoxico]

I have roxul stuffed in the smoke shelf but no steel block off plate , i would say my reading of 60 degrees would be just above the insert

Sounds like you know what you gotta do. Block off plate an inch or two above the lintel, fill w/ Roxul above right around the liner. Metal will reflect heat into the room and the added Roxul will keep your liner from giving up so much heat to the brick.

 

[jatoxico]

This is mine. You can see the lintel in this pic. Area above is stuffed as full as I could w/ Roxul insulation.

 

[bholler]

I have roxul stuffed in the smoke shelf but no steel block off plate , i would say my reading of 60 degrees would be just above the insert

And is the liner insulated?

 

[etiger2007]

liner is not insulated , i have no creosote build up at all. This spring ill pull the insert out and install a proper block off plate. This should keep the insert hotter longer i would guess!

 

[Jags]

Uninsulated liner and no block of plate (insulation is NOT an air barrier). This is the exact reason that both are highly suggested around here.

 

[mellow]

Yea, as I stated in my thread the roxul alone was not working, cement board + roxul worked.

 

[etiger2007]

Im on it guys, Mellow when you corrected yours what benefits did you see?

 

[bholler]

Also with the liner being uninsulated you are obviously going to give up a fair amount of heat to the structure.

 

[mellow]

Im on it guys, Mellow when you corrected yours what benefits did you see?

Its all in the thread back in 2013: https://www.hearth.com/talk/threads...lating-my-fireplace.75755/page-2#post-1598099

 

[Wisneaky]

so i read a thread awhile ago and mello used a infrared thermo on the outside of his chimney, cant remember his readings but it was 28 outside today and i thought i would check my chimney on the out side , so i hit it with the infrared and my chimney on the outside read 60 degrees on the outside, readings were 30 to 60 degrees, my insert is wrapped in Roxul and also surounded by a steel heatalator steel box, what else can i do to keep the heat contained to the house and not seep through the chimney ? Gotta be losing a ton of heat right?

are you taking the temperature on the metal? Infrared thermometers don't take accurate readings on bare metal.

 

[mellow]

are you taking the temperature on the metal? Infrared thermometers don't take accurate readings on bare metal.

Masonry chimney.

 

[Wisneaky]

Masonry chimney.

so that the outside masonry chimney with a liner installed? Temps sound about right to me. My chimney with a liner installed runs about 60-80 degrees normally.

 

[mellow]

You would be wise to read the link I posted above.

 

[Wisneaky]

I'm running a wood furnace so it doesn't apply to me. My liner is also double walled and insulated.

You would be wise to read the link I posted above.

I'd like to know what your inside flue temp was with and without your changes? Maybe more heat was going up the inside of the flue instead of into the masonry chimney after the changes? Just because the masonry was cooler doesn't mean that this translates to more heat inside your house.

 

[mellow]

I just did start monitoring my flue temps this year, not easy to do with an insert. The heat is being pushed out via the fan on the insert as the firebox is hotter and the fire lasts longer so it is not just going up the flue.

 

[Wisneaky]

I just did start monitoring my flue temps this year, not easy to do with an insert. The heat is being pushed out via the fan on the insert as the firebox is hotter and the fire lasts longer so it is not just going up the flue.

sound like its better for you.

 

[jatoxico]

I'd like to know what your inside flue temp was with and without your changes? Maybe more heat was going up the inside of the flue instead of into the masonry chimney after the changes? Just because the masonry was cooler doesn't mean that this translates to more heat inside your house.

I had similar experience to Mellow's post above after putting in proper plate and insulating as best I could. I cannot easily measure my flue temps either, but regardless of whether some of the heat is "going up the flue" (better heat retention in the flue means better performance) or if the heat made it to the room (prob bit of both) still better than it going to an inexhaustible heat sink low in the system like the great outdoors.

 

[CaptSpiff]

so i read a thread awhile ago and mello used a infrared thermo on the outside of his chimney, cant remember his readings but it was 28 outside today and i thought i would check my chimney on the out side , so i hit it with the infrared and my chimney on the outside read 60 degrees on the outside, readings were 30 to 60 degrees, my insert is wrapped in Roxul and also surrounded by a steel heatalator steel box, what else can i do to keep the heat contained to the house and not seep through the chimney ? Gotta be losing a ton of heat right?

Hi Ed,
Is the old steel box Heatalator the same as in your avatar? I had an old (1973?) steel box fireplace with the heat tubes welded to the backside. Tubes took in room air at the lower left & right, then tubes penetrated the steel box below the damper plate (fully subjected to the flue gas stream), then they penetrated the upper front of the box to exhaust their heated air into the room above the lintel. The whole box is enclosed in a full masonry chimney with full tile liner. It was a monster heat maker in its day, but it ate my wood supply like a bonfire. When it wasn't used it was cold as ice, sucked the heat right out of the room.

When I converted it to an insert I found that the tubes were pulling the heat from the steel box and heating the air space between the steel box and the exterior brick. My solution was to pour some chimney insulation mix down the tubes. Then I fitted 1/2 inch thick pieces of cement board to the steel box inside walls. Seemed to help a bit, but if I were doing it again I'd cut hand holes into the upper back of the steel box and pour the insulation mix right into the voids behind the steel box. I suspect there are 6 to 8 inch voids behind the steel box with only a layer of brick separating the outside world. If your is an inside chimney then the above doesn't really apply.

I also second the insulated blockoff plate. Too bad you didn't insulate the liner too.

 

[etiger2007]

Hi Ed,
Is the old steel box Heatalator the same as in your avatar? I had an old (1973?) steel box fireplace with the heat tubes welded to the backside. Tubes took in room air at the lower left & right, then tubes penetrated the steel box below the damper plate (fully subjected to the flue gas stream), then they penetrated the upper front of the box to exhaust their heated air into the room above the lintel. The whole box is enclosed in a full masonry chimney with full tile liner. It was a monster heat maker in its day, but it ate my wood supply like a bonfire. When it wasn't used it was cold as ice, sucked the heat right out of the room.

When I converted it to an insert I found that the tubes were pulling the heat from the steel box and heating the air space between the steel box and the exterior brick. My solution was to pour some chimney insulation mix down the tubes. Then I fitted 1/2 inch thick pieces of cement board to the steel box inside walls. Seemed to help a bit, but if I were doing it again I'd cut hand holes into the upper back of the steel box and pour the insulation mix right into the voids behind the steel box. I suspect there are 6 to 8 inch voids behind the steel box with only a layer of brick separating the outside world. If your is an inside chimney then the above doesn't really apply.

I also second the insulated blockoff plate. Too bad you didn't insulate the liner too.

Yes the old steel box type. I do have a void between the steel box and the brick chimney, i tried filling that void with chunks on roxul, this didnt work very well. My "tubes , 3 of them" were only located in the smoke shelf , I had to remove the middle one to get my liner down the chimney. I read Mellows report on his block off plate and will mirror it this summer. As far as the insulation of the liner, I dont really see what difference that would make since its only there to warm the air so crosote is less likely to form, I have never had a crosote problem so far, does the insulation of the liner effect burn time and performance?

 

[mellow]

I have never had a crosote problem so far, does the insulation of the liner effect burn time and performance?

If your draft is fine and your creosote is minimal I do not see the need for insulation as long as you had your existing chimney thoroughly checked before the liner was installed.

Insulation is good to have but not always required, especially since you have a tube reburner.

 

[jatoxico]

Yes the old steel box type. I do have a void between the steel box and the brick chimney, i tried filling that void with chunks on roxul, this didnt work very well. My "tubes , 3 of them" were only located in the smoke shelf , I had to remove the middle one to get my liner down the chimney. I read Mellows report on his block off plate and will mirror it this summer. As far as the insulation of the liner, I dont really see what difference that would make since its only there to warm the air so crosote is less likely to form, I have never had a crosote problem so far, does the insulation of the liner effect burn time and performance?

My liner is not insulated either and I get by but I do think anything that helps with heat retention would be a plus. If the liner can hold its heat better then theoretically you could run the stove w/ less air, extending burn time while still keeping flue gasses above the 220 ish you need to keep from forming creosote.

The way I think about it is that with the block off plate you are isolating the stove from the chimney. Previously my liner and stove top used to give up a lot of heat that was trapped behind the surround that would mostly get lost to the exterior brick but not really doing any good as far as heating the room (stove's job) or keeping the flue gases as hot as possible (chimney's job). Now heat from the stove goes into the room and the heat from the flue is retained better so I had a cleaner system last time I cleaned.