question about secondaries

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FramerJ

New Member
Mar 18, 2021
42
Missouri
I have a new PE Neo 2.5 non-cat insert. 6" insulated flex liner, 15' flue. The Neo only has primary air control. I am still learning my insert. I am burning soft maple (I think) because that is all I have seasoned for this winter. It is dry according to my MM 10-15% and it catches fire before I can even finish reloading at times. So 20-30 minutes after I reload, I have a raging inferno going. I start to close the air down in small increments at a time, approx. 25%. Still Raging inferno. I wait another 5-10 min and close the air some more. By this time, my glass starts to turn hazy. Starts in the top corners then continues down and almost to the bottom middle, like a flat “U”. After 5-10min, I continue to turn the air down to 2/3 to ¾ closed. By now, the firebox isn’t a full raging fire but mostly secondaries. And not the "northern lights" kind. It looks like there are 62 mini torches on the top of the firebox pointing down. However, the glass is more dirty than hazy and getting dirtier. This is about 40-45 minutes after reloading on hot coals. I experiment some more and open the air back up all the way. The glass goes clear in less than a minute. What is going on? Why I am getting dirty glass with secondaries going like that? If I leave the air all the way open, I have nice clear glass for the whole burn cycle but my firewood is burned down to coals in 1.5 hours. I have kept the air closed down other times and some of glass gets burned clean but not all of it and not all the time. I am sure with better hardwood firewood and larger splits, I will get longer burn times but for the time being, I am just trying to understand what is going on in this particular instance. Im guessing my firewood is burning too hot too fast before I can turn my air down properly? My apologies if this has been previously discussed. I really try to search and read all prior posts before bugging you all.
 

ABMax24

Minister of Fire
Sep 18, 2019
1,442
Grande Prairie, Alberta, Canada
Turn the damper down much sooner, if the wood is caught by time you close the door you can probably shut the damper at that time, as long as you have secondary burn occurring you are golden.

The glass gets dirty from the wood gas condensing on the glass, you simply have so much wood gas in the firebox, it condenses on anything cold. This is simply because the wood is so dry is offgasses very quickly, it's also being reloaded on hot coals allowing to offgas quickly, and you are leaving the damper open further encouraging it to offgas. It burns off when you open the damper because it gets a rush of air which the burns these condensed gases.

As you have found opening the damper just enlarges the inferno, probably getting the stove and flue too hot, sending unburnt woodgas up the flue as smoke and soot, and also resulting in very short burn time. Softwoods are also worse for this issue, the pitch offgasses faster.
 

stoveliker

Minister of Fire
Nov 17, 2019
4,353
Long Island NY
I think you need to shut the air sooner.

Edit: ah. See above.

Edit 2: but congrats on starting with a modern stove with appropriately seasoned wood! Not many can say that. It's a learning curve, but it'll be a better result in the end.
 

FramerJ

New Member
Mar 18, 2021
42
Missouri
Turn the damper down much sooner, if the wood is caught by time you close the door you can probably shut the damper at that time, as long as you have secondary burn occurring you are golden.

The glass gets dirty from the wood gas condensing on the glass, you simply have so much wood gas in the firebox, it condenses on anything cold. This is simply because the wood is so dry is offgasses very quickly, it's also being reloaded on hot coals allowing to offgas quickly, and you are leaving the damper open further encouraging it to offgas. It burns off when you open the damper because it gets a rush of air which the burns these condensed gases.

As you have found opening the damper just enlarges the inferno, probably getting the stove and flue too hot, sending unburnt woodgas up the flue as smoke and soot, and also resulting in very short burn time. Softwoods are also worse for this issue, the pitch offgasses faster.
Sweet. I like it when the problem is me--thats an easy fix.
That all makes sense. Thanks for the quick reply
I think you need to shut the air sooner.

Edit: ah. See above.

Edit 2: but congrats on starting with a modern stove with appropriately seasoned wood! Not many can say that. It's a learning curve, but it'll be a better result in the end.
Thanks for replying and the consensus with my problem.
Unfortunately, I wont have enough firewood for this winter but I do have 5 cords seasoning. Thanks to you guys.
 

ABMax24

Minister of Fire
Sep 18, 2019
1,442
Grande Prairie, Alberta, Canada
Sweet. I like it when the problem is me--thats an easy fix.
That all makes sense. Thanks for the quick reply

Thanks for replying and the consensus with my problem.
Unfortunately, I wont have enough firewood for this winter but I do have 5 cords seasoning. Thanks to you guys.

Yup, easy peasy. I actually like burning wood in the 14-16% range, throw it in on the coals, turn the damper down, walk away. No burning in or charring the wood first.
 
Last edited:

stoveliker

Minister of Fire
Nov 17, 2019
4,353
Long Island NY
Sweet. I like it when the problem is me--thats an easy fix.
That all makes sense. Thanks for the quick reply

Thanks for replying and the consensus with my problem.
Unfortunately, I wont have enough firewood for this winter but I do have 5 cords seasoning. Thanks to you guys.
You could try to get some pallets for free. They are dry...
Or buy a pallet of sawdust logs (get the ones without wax or other additives). But that costs..

Easy fix in principle, but maybe some playing around anyway. At least you start from the right side of the optimization curve.
 

FramerJ

New Member
Mar 18, 2021
42
Missouri
You could try to get some pallets for free. They are dry...
Or buy a pallet of sawdust logs (get the ones without wax or other additives). But that costs..

Easy fix in principle, but maybe some playing around anyway. At least you start from the right side of the optimization curve.
I'm a rough-in framer so I have a bunch of 2x4 scraps to use as well. I have been throwing in a couple scraps with the maple to supplement my remaining firewood. But they are spruce/Doug fir so they burn just as fast. However it's free.

I have thoroughly enjoyed playing around and experimenting with this insert. It's been a learning experience for sure.
 

stoveliker

Minister of Fire
Nov 17, 2019
4,353
Long Island NY
I'm a rough-in framer so I have a bunch of 2x4 scraps to use as well. I have been throwing in a couple scraps with the maple to supplement my remaining firewood. But they are spruce/Doug fir so they burn just as fast. However it's free.

I have thoroughly enjoyed playing around and experimenting with this insert. It's been a learning experience for sure.
There'll be more playing in the years to come :)
If you have marginal wood (a bit too wet), you can mix with the 2x4s. If you only have fresh wood left (much too wet), then it doesn't make much sense I think.
 

MR. GLO

Feeling the Heat
Jan 26, 2021
352
Massachusetts
I'm guessing wood issue. I have a new pe summit and never get dirty glass.... Except once when I add a piece of wet wood that git mixed in by error.

been running it 24/7 for the last week but got wood several years ago...

What does the inside look like can you send us a picture of fire bricks when not running or hot.
 

xman23

Minister of Fire
Oct 7, 2008
2,431
Lackawaxen PA
It may not be that easy to correct now. But try the suggestions.
My story was the oak wood I was burning. I was convinced the stove couldn't be run without blacking the glass. It took a few years before the total blacken glass every weekend started to get better. The wood got seasoned. Many years since then, same wood, and I have to smolder the fire or have a butt end near the glass to blacken a small spot. Most of the season it stays clean. Burn a full hot load and choke it down. The secondary air washes the glass, burning off any black area. A bit of white haze that can be burned off as well. But when it's cold it cleans up with a wet paper towel. I like spotless glass. So if it's not I use spray nine fireview.
 

FramerJ

New Member
Mar 18, 2021
42
Missouri
I'm guessing wood issue. I have a new pe summit and never get dirty glass.... Except once when I add a piece of wet wood that git mixed in by error.

been running it 24/7 for the last week but got wood several years ago...

What does the inside look like can you send us a picture of fire bricks when not running or hot.
My bricks are cleaner than they were brand new. I have been running hot fires. Im new to wood burning so I have been erring on the side of hotter but shorter fires than trying to go for longer burn times. Just trying to establish a baseline to work with and go from there.

I will never dimiss the chance of a wet piece of firewood getting mixed in. I dont check every piece with a MM. However, I felt my situation was too constant to account for a rogue piece of wet firewood.

Glad to hear from someone with a "sister" wood burner. That does help with comparisons to my insert. All advice is appreciated.
It may not be that easy to correct now. But try the suggestions.
My story was the oak wood I was burning. I was convinced the stove couldn't be run without blacking the glass. It took a few years before the total blacken glass every weekend started to get better. The wood got seasoned. Many years since then, same wood, and I have to smolder the fire or have a butt end near the glass to blacken a small spot. Most of the season it stays clean. Burn a full hot load and choke it down. The secondary air washes the glass, burning off any black area. A bit of white haze that can be burned off as well. But when it's cold it cleans up with a wet paper towel. I like spotless glass. So if it's not I use spray nine fireview.
Oh I will be trying the suggestions with closing the damper sooner once I get another fire going. This is not my main source of heat....yet.
I have just been burning some soft maple. I do have a couple cords of oak but I dont plan on touching those for 2 more years.
I have not had any black build up so thats good. Just some hazy gray stuff depending on how I am using my insert. Still learning how to use it. Most of the time, I can just wipe with a wet paper towel and get very little residue. I like spotless glass as well.
Thanks for replying to my post. I appreciate it.
 
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