Chimney 14' do I need a damper?

[mpjohnny5]

Hi guys I was hoping I could get some help. I think I'm getting too much draft on my heritage even when the primary air is full closed. Reason being with well seasoned wood and now even biobricks to test I can't get burn times longer than 4 hrs it seems. Secondaries will only stay going for about an hour I'd say once everything's charred and flue temps are at 400. My setup is 6 inch single wall 14 feet up in the living room cathedral ceilings. A pair of 45s before it exits with class A 2 feet over the peak.

I'm wondering if because of the length of chimney I'm pulling too much draft and the stove could be overfiring why I'm burning up fuel so fast? Is there a test for this or should I just install a damper? And if the dampers the trick where should I install right on top of stove before pipe connects or after the first 4 footer of piping? Any advice/help much appreciated here just trying to get some longer burn times.

 

[nate379]

I wouldn't expect that you'd have too much draft with only 14ft of pipe, but each install is different.

I had about about the same length and I had to add another 3 ft for more draft.

 

[pen]

That chimney is at the low end of recommended chimney height so I'm doubting it is in need of a damper.

How long are you keeping the air wide open before turning it down and letting the stove cruise?

How open (or closed depending on how you look at it) are you keeping your air settings once you are cruising?

Is that 400 degree temp on single or double wall pipe? Is that a magnetic or probe thermometer? How far above the stove top is it?

pen

 

[begreen]

We need to know the total flue system length. What is the total length of class A pipe?

Also, can you describe how you are loading the stove and what wood you are burning?

Note: Long runs of single wall connector are not recommended.

 

[mpjohnny5]

K i Just measured guys its just under 15 ft on single wall to the ceiling, then 3 feet of class A through the roof.

Ive been using biobricks this year, but had the same problem last year which was my first year after the install with good seasoned wood. I build it the same way biobricks shows on there site, tepee to start then stack in 11 total bricks tight leaving door ajar till there all caught. Then I shut the door leaving air wide open till everythings charred and flue temp is 400 or up. That temp reading is on the single wall pipe about 2 feet above the stove on a magnetic thermometer not probe. Then I slowly close the air ( to the right) till its a touch above shut. Even when I do this much closing of the air it still seems like air is still rushing in. You can almost hear it faintly when its quiet.

I know you guys always question the wood which is well justified as this is a major part of newbies problems, but a 20 year burner friend of mine who is well ahead with his wood gave me some of his best last year to start off. Mostly oak and hickory, same story...

 

[begreen]

Thanks, so 18ft total. That is just about ideal. But I can appreciate that your burn has not been so. Has the stove been carefully checked over for air leaks and gasket issues? How does the stove respond to the air control? Where do you have it set for the long burn?

11 BioBricks is only 22# of fuel IIRC. If there are no air leaks, and control is good, I would try adding another layer at right angles on top of the current layer for a longer burn. For cordwood, here's a shot of Highbeam's loading of the stove. Is you load similar?

https://www.hearth.com/econtent/index.php/forums/viewthread/87007/P22/#1055363

 

[mpjohnny5]

Thanks, so 18ft total. That is just about ideal. But I can appreciate that your burn has not been so. Has the stove been carefully checked over for air leaks and gasket issues? How does the stove respond to the air control? Where do you have it set for the long burn?

11 BioBricks is only 22# of fuel IIRC. If there are no air leaks, and control is good, I would try adding another layer at right angles on top of the current layer for a longer burn. For cordwood, here's a shot of Highbeam's loading of the stove. Is you load similar?

https://www.hearth.com/econtent/index.php/forums/viewthread/87007/P22/#1055363

No the stove is new last year and installed by myself. Each pipe joint used HIGH temp silicone, not sure how else the stove would checked for air leaks gasket issues? The stove responds by secondarys kicking in as soon as the air is lowered down to about halfway. (the problem being how long they stay roaring) I close the air all the way to right and then open it a quarter or less I would say. Not sure what you mean by 22#? Yes when I was burning cordwood that is exactly how I would load it. I even tried north south burning with some 9 inch splits I had and would really load it up.

 

[mpjohnny5]

oh and 11-12 bricks will get me 500 degrees on the center stone top. But it will not stay burning like this for long. The stone will naturally hold its heat of course, but the actually burn time is 3 maybe 4 hours. By then its just solid bricks no flames

 

[begreen]

22# = 22 lbs. Each BioBrick = 2lbs.

Solid bricks, no flame can be ok as long as they are still in the charcoal stage. That lasts a long time with BioBricks and there should still be significant heat output from them. They should be glowing red and you should still see wispy blue flames coming off of them at this stage.

 

[mpjohnny5]

Ok so then what does it it take to get up to 8 hrs of burn time and 12 hrs of heat as advertised for the heritage? And I understand Im using biobricks which isnt same as cordwood, but like I said before I never got even close to that with wood last year. Which is what led me to believe in the damper situation. Isnt there a way to measure you draft and see?

 

[begreen]

Yes, draft can be measured with a magnehelic gauge. Here's what it says in the manual:

Long runs of stovepipe to increase heat dispersal are not
recommended. Using longer lengths of stovepipe or more
connecting elbows than necessary increase the chances of
draft resistance and the accumulation of creosote buildup.

In general, you do not need to install a stovepipe damper
with the Heritage. Some installations, however, could
benefit from a stovepipe damper, such as a tall chimney
which can create a higher than normal draft. In such
cases, a damper can help regulate the draft. The Heritage
requires a draft between 0.06" wc and 0.1" wc. For drafts
above 0.1" wc, install a stovepipe damper. This should be
checked at installation time.


For longer burn times, it may take more fuel. How did your full wood load compare to the shot of Highbeam's full load that I posted?

I would forget about advertised burn time or heat. That is totally a subjective, vague number most often used by marketing. And what is burn time? Do you have coals enough for a restart after 8 hrs.? If yes, fine. That's the way some define burntime. Is the stove still warm after 12 hrs.? Well then, we have heat. I'm kidding of course by wearing the marketing hat to illustrate.

 

[oldspark]

Did you ever try a dollar bill test, if you are getting too much air it could be a door gasket.