damper, flue temp question

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My Oslo heats my home

Minister of Fire
Hearth Supporter
Sep 20, 2010
1,584
South Shore, MA
I have been asking here for about a week regarding lower burn times. I resealed the doors with new gasket just to eliminate that and I installed a damper today to help with the strong draft on a 26' flue.

After working different positions on the damper I have found this has helped with the burn times considerably already. My question is about flue temps before and after the damper itself.

Since I did not have a flue thermometer I'll be making my way to pick one up shortly.

So, my apologies for the short timed request but my thoughts are about getting a decent overnight burn tonight. I'm using the stovetop therm on the stovepipe for now.
 
Measure the temperature as per the instructions on the thermometer (I have had best luck with condars which I believe call for being 18 inches up from the stove collar).

My pipe damper is between the thermometer and the stove.

Things will vary, sometime but in general, there is no reason you couldn't run with just one thermometer as you were doing before. Having two is just more data and you can learn what is normal for each.

pen
 
Measure the temperature as per the instructions on the thermometer (I have had best luck with condars which I believe call for being 18 inches up from the stove collar).

My pipe damper is between the thermometer and the stove.

Things will vary, sometime but in general, there is no reason you couldn't run with just one thermometer as you were doing before. Having two is just more data and you can learn what is normal for each.

pen
So the 18" above the stove is the number I should be concerned with only. Having the damper installed put my mind immediately into panic mode ( because it was something new ) and knowing that if I choked it too much that I would get high temps before the damper which in turn would give me well below on the other side.
At what temp would I look for at 18", to avoid the flue from being too cold and the issues associated with any buildup?

I'm sure this will be a trial and error phase until I get the hang of it.
 
Here's the one I put on my pipe.

(broken image removed)

But it's a matter of taste.

This is another from Condar with a different paint job

[Hearth.com] damper, flue temp question


I tend to think this scale is pretty decent, at least for the top end where 475 should be the max burn rate for the stove pipe. I find that if I'm cruising at the "redline" on the stove pipe, that my stove top is at the "redline" for it's thermometer as well.

[Hearth.com] damper, flue temp question

Here's an example of the condar stove top thermometer with a different scale on it to match the stove top. This is better than the rutlands and some other thermometers that claim to be good for each so they use a scale that is averaged, which makes it worthless for each IMO.

Now for my stove, I consider the redline a bit higher than what is shown on the thermometer, so I move the thermometer to a spot that consistently reads 25 to 50 degrees cooler than the hottest spot on the stove. That way, it keeps things simple for the lady of the house. She doesn't need to remember any numbers, just knows that if she's running the stove to keep things out of the TOO HOT zone for either thermometer.

pen
 
Sorry, just had some coffee and went to double check the 18 inches i mentioned.

I found for my setup 18 inches up the pipe is where I have readings that consistently line up the "redline" for both the stove top and stove pipe thermometers.

Condars instructions say to place the thermometer at least 12 inches above the top of the stove.

You'll have to play a bit to find the sweet spots for yours. A IR thermometer helped me.

At the end of the day, I'm not very concerned about the exact stove top or pipe temp as I think that's way too nitty-gritty considering the manufacturers of most stoves claim your fine until something is emitting light (glowing red). I wanted to set up easy to read thermometers to make it simple for the wife to understand that it is possible to over heat the stove pipe well before the stove gets up to temp, and give her general "redlines" to work from to keep things easy so she doesn't get stressed.

pen
 
Sorry, just had some coffee and went to double check the 18 inches i mentioned.

I found for my setup 18 inches up the pipe is where I have readings that consistently line up the "redline" for both the stove top and stove pipe thermometers.

Condars instructions say to place the thermometer at least 12 inches above the top of the stove.

You'll have to play a bit to find the sweet spots for yours. A IR thermometer helped me.

At the end of the day, I'm not very concerned about the exact stove top or pipe temp as I think that's way too nitty-gritty considering the manufacturers of most stoves claim your fine until something is emitting light (glowing red). I wanted to set up easy to read thermometers to make it simple for the wife to understand that it is possible to over heat the stove pipe well before the stove gets up to temp, and give her general "redlines" to work from to keep things easy so she doesn't get stressed.

pen
Ok, thank you for the info on the thermometers on the stove pipe and how to find the sweet spot. I have been working on that over the last couple days. Today is a warm day outside so I may be burning like a shoulder day.

Now, another question on the damper itself. I have found that when the damper is about 3/4 closed the draft is alot more regulated and the burning becomes more even. Can this be the standard for me? I have a regularly strong draft but this whole damper thing is new to me. Last night, for the first time I closed the damper nearly all the way, this morning after 10 hrs of overnight burning I had a stovetop temp of 250 and a nice bed of smaller coals for the restart.
 
Ok, thank you for the info on the thermometers on the stove pipe and how to find the sweet spot. I have been working on that over the last couple days. Today is a warm day outside so I may be burning like a shoulder day.

Now, another question on the damper itself. I have found that when the damper is about 3/4 closed the draft is alot more regulated and the burning becomes more even. Can this be the standard for me? I have a regularly strong draft but this whole damper thing is new to me. Last night, for the first time I closed the damper nearly all the way, this morning after 10 hrs of overnight burning I had a stovetop temp of 250 and a nice bed of smaller coals for the restart.

Sure, that may be your normal.

Just remember, as you are changing your burning style, to keep a closer eye on the chimney just to make sure the experimentation isn't leaving more build-up than you are used to.

Sounds like you are on the right track.

pen
 
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