Am I expecting too much???

[Woodcutter Tom]

I am also am in suspect of the wood. Any moisture in the wood cools off the burn tubes, canceling out any chance of secondary burn. I would mix some pine 2x4s with the ash and give it another try. Remember you need a bed of coals raked forward in the stove, then add 6-8 splits on the coals. All my hardwood is tried 2 years and I have never seen moisture readings as low as yours. Something seems strange. 13-15% on hardwood almost needs to be dried in a Kiln or stored in a garage for 5 years. Most of my hardwood is 18-20% moisture and burns very well. Usually non-cats burn in the opposite manner, very hot in the beginning of the burn. For example, my experience is stove top temps range from 600-750 within the first hour or two of a fresh load.

When I pick up the walnut, it feels like balsa wood. very light.
I have a fire going now......without much success. When it burns down to coals, I will throw in 3 bricks of compressed sawdust.

 

[begreen]

The walnut might be sapwood if it's light colored. That will have lower density and less btus. Walnut is on the low side for btus for hardwoods, but still a decent firewood.

 

[Woodcutter Tom]

The walnut might be sapwood if it's light colored. That will have lower density and less btus. Walnut is on the low side for btus for hardwoods, but still a decent firewood.

Not sapwood. Was split into smaller pieces. I have a few bigger pieces that have higher MC.

 

[Woodcutter Tom]

I am also am in suspect of the wood. Any moisture in the wood cools off the burn tubes, canceling out any chance of secondary burn. I would mix some pine 2x4s with the ash and give it another try. Remember you need a bed of coals raked forward in the stove, then add 6-8 splits on the coals. All my hardwood is tried 2 years and I have never seen moisture readings as low as yours. Something seems strange. 13-15% on hardwood almost needs to be dried in a Kiln or stored in a garage for 5 years. Most of my hardwood is 18-20% moisture and burns very well. Usually non-cats burn in the opposite manner, very hot in the beginning of the burn. For example, my experience is stove top temps range from 600-750 within the first hour or two of a fresh load.

I found some 2 x 4 and used them with Ash. Attached pictures are what I loaded.

Here is summary of what happened. It did not take very long for the flue to reach temps in the 750 F range. Just minutes. I shut the Primary Air (PA) 1/2 way. Very quickly the flue dropped to 625F. I adjusted the PA to 1/4 closed. The flue went up to 750 to 770 then up to 815. The primary air flow by the glass started to ignite the unburned gasses. There was some secondary burning from the tubes but not robust.
When the flue reached 830 F I closed the PA 1/2 way. The flue continued to rise to 870. The STT was 400. There were flames across the top of the stack, but not secondary flames.
At 15 minutes into the burn, the flue was 845, the manometer was .14. I shut the damper 1/2 way. 1 minutes later I shut the PA completely closed. Manometer dropped to .07. The flue was 865. STT approaching 450. Within 8 minutes the flue had started to rapidly rise. The primary air by the glass was igniting more and more of the unburned gas. I closed the damper fully.
Now the damper is fully closed; the PA is fully closed and the flames by the glass are increasing. For the next 1/2 hour the flue is 900 - 925 F. The manometer is .06 - .075. The STT rises to about 590 F. Most of the flames I see are the flames from the unburned gasses being ignited by the primary air coming down in front of the glass. The bottom of the glass gets dirty as the hot air wsh air never reachs that far down. This is the same thing that has happen before, but it was not as intense. I did not get the flue in the 1100 F range. There was more ignition of the gasses by the air from the tubes, and that lead to higher STT than before. But once the primary air starts igniting the gasses, it does not stop till the wood is burned out. I don't think it is the wood dryness. I think the draft may still be too much. If .03 - .05 is the goal, I was never close. And I had the damper and the primary air completely shut. At that point I can only watch.
I am wondering how to shut the draft down even more.

 

[brenndatomu]

I am wondering how to shut the draft down even more.

I mentioned this in one of your threads the other day...for further draft control you need to block those holes in the damper plate...just place some fender washers on each side of the holes and run a bolt through to hold in place.
Partially blocking the PA and SA intake holes can have somewhat the same affect too...but now you are screwing the the primary/secondary air ratios somewhat too...I'd rather just drop the draft with the damper personally

 

[Mike M.]

I found some 2 x 4 and used them with Ash. Attached pictures are what I loaded.

Here is summary of what happened. It did not take very long for the flue to reach temps in the 750 F range. Just minutes. I shut the Primary Air (PA) 1/2 way. Very quickly the flue dropped to 625F. I adjusted the PA to 1/4 closed. The flue went up to 750 to 770 then up to 815. The primary air flow by the glass started to ignite the unburned gasses. There was some secondary burning from the tubes but not robust.
When the flue reached 830 F I closed the PA 1/2 way. The flue continued to rise to 870. The STT was 400. There were flames across the top of the stack, but not secondary flames.
At 15 minutes into the burn, the flue was 845, the manometer was .14. I shut the damper 1/2 way. 1 minutes later I shut the PA completely closed. Manometer dropped to .07. The flue was 865. STT approaching 450. Within 8 minutes the flue had started to rapidly rise. The primary air by the glass was igniting more and more of the unburned gas. I closed the damper fully.
Now the damper is fully closed; the PA is fully closed and the flames by the glass are increasing. For the next 1/2 hour the flue is 900 - 925 F. The manometer is .06 - .075. The STT rises to about 590 F. Most of the flames I see are the flames from the unburned gasses being ignited by the primary air coming down in front of the glass. The bottom of the glass gets dirty as the hot air wsh air never reachs that far down. This is the same thing that has happen before, but it was not as intense. I did not get the flue in the 1100 F range. There was more ignition of the gasses by the air from the tubes, and that lead to higher STT than before. But once the primary air starts igniting the gasses, it does not stop till the wood is burned out. I don't think it is the wood dryness. I think the draft may still be too much. If .03 - .05 is the goal, I was never close. And I had the damper and the primary air completely shut. At that point I can only watch.
I am wondering how to shut the draft down even more.

Just my observation-the moisture test needs to be on a fresh split face of the wood and the meter needs to be stabbed into the wood. Also I would orient the wood straight in the stove leaving a path for primary air to hit the back wall of the stove. I have never been really successful with east / west loading with no air path like the picture.

 

[jetsam]

With a not-quite-12' flue, this really shouldn't have veered into a conversation about draft reduction even if it didn't have a damper on it already.

I feel like you should be making sure your secondaries are operating properly, and then thinking about moving cold air to the stove and checking the envelope to see if BTU load is excessive. An outside air kit might be part of the fix if other parts of the house are getting very cold.

 

[bholler]

I found some 2 x 4 and used them with Ash. Attached pictures are what I loaded.

Here is summary of what happened. It did not take very long for the flue to reach temps in the 750 F range. Just minutes. I shut the Primary Air (PA) 1/2 way. Very quickly the flue dropped to 625F. I adjusted the PA to 1/4 closed. The flue went up to 750 to 770 then up to 815. The primary air flow by the glass started to ignite the unburned gasses. There was some secondary burning from the tubes but not robust.
When the flue reached 830 F I closed the PA 1/2 way. The flue continued to rise to 870. The STT was 400. There were flames across the top of the stack, but not secondary flames.
At 15 minutes into the burn, the flue was 845, the manometer was .14. I shut the damper 1/2 way. 1 minutes later I shut the PA completely closed. Manometer dropped to .07. The flue was 865. STT approaching 450. Within 8 minutes the flue had started to rapidly rise. The primary air by the glass was igniting more and more of the unburned gas. I closed the damper fully.
Now the damper is fully closed; the PA is fully closed and the flames by the glass are increasing. For the next 1/2 hour the flue is 900 - 925 F. The manometer is .06 - .075. The STT rises to about 590 F. Most of the flames I see are the flames from the unburned gasses being ignited by the primary air coming down in front of the glass. The bottom of the glass gets dirty as the hot air wsh air never reachs that far down. This is the same thing that has happen before, but it was not as intense. I did not get the flue in the 1100 F range. There was more ignition of the gasses by the air from the tubes, and that lead to higher STT than before. But once the primary air starts igniting the gasses, it does not stop till the wood is burned out. I don't think it is the wood dryness. I think the draft may still be too much. If .03 - .05 is the goal, I was never close. And I had the damper and the primary air completely shut. At that point I can only watch.
I am wondering how to shut the draft down even more.

Shut the air down sooner.

 

[begreen]

I found some 2 x 4 and used them with Ash. Attached pictures are what I loaded.

Here is summary of what happened. It did not take very long for the flue to reach temps in the 750 F range. Just minutes. I shut the Primary Air (PA) 1/2 way. Very quickly the flue dropped to 625F. I adjusted the PA to 1/4 closed. The flue went up to 750 to 770 then up to 815. The primary air flow by the glass started to ignite the unburned gasses. There was some secondary burning from the tubes but not robust.
When the flue reached 830 F I closed the PA 1/2 way. The flue continued to rise to 870. The STT was 400. There were flames across the top of the stack, but not secondary flames.
At 15 minutes into the burn, the flue was 845, the manometer was .14. I shut the damper 1/2 way. 1 minutes later I shut the PA completely closed. Manometer dropped to .07. The flue was 865. STT approaching 450. Within 8 minutes the flue had started to rapidly rise. The primary air by the glass was igniting more and more of the unburned gas. I closed the damper fully.
Now the damper is fully closed; the PA is fully closed and the flames by the glass are increasing. For the next 1/2 hour the flue is 900 - 925 F. The manometer is .06 - .075. The STT rises to about 590 F. Most of the flames I see are the flames from the unburned gasses being ignited by the primary air coming down in front of the glass. The bottom of the glass gets dirty as the hot air wsh air never reachs that far down. This is the same thing that has happen before, but it was not as intense. I did not get the flue in the 1100 F range. There was more ignition of the gasses by the air from the tubes, and that lead to higher STT than before. But once the primary air starts igniting the gasses, it does not stop till the wood is burned out. I don't think it is the wood dryness. I think the draft may still be too much. If .03 - .05 is the goal, I was never close. And I had the damper and the primary air completely shut. At that point I can only watch.
I am wondering how to shut the draft down even more.

The splits are pretty skinny. They would be kindling in our stove. They very likely are dry. This goes back to the premise that the wood is outgassing too rapidly due to the small split size.

 

[Woodcutter Tom]

I mentioned this in one of your threads the other day...for further draft control you need to block those holes in the damper plate...just place some fender washers on each side of the holes and run a bolt through to hold in place.
Partially blocking the PA and SA intake holes can have somewhat the same affect too...but now you are screwing the the primary/secondary air ratios somewhat too...I'd rather just drop the draft with the damper personally

I saw that idea and consider it as a way to test.
I still feel that the primary/secondary air ratio is screwy. Else I would get robust secondary tube flames prior to the primary air igniting gasses.
I now have a SBI tech phone number. I'll try to talk to them next week.

 

[Woodcutter Tom]

Just my observation-the moisture test needs to be on a fresh split face of the wood and the meter needs to be stabbed into the wood. Also I would orient the wood straight in the stove leaving a path for primary air to hit the back wall of the stove. I have never been really successful with east / west loading with no air path like the picture.

This was a test. The ash was split fresh and then measured. The 2 x 4s were cut to length. The short unused pieces was split, then measured. The walnut display was for visual purposes. Wood was stabbed.
I normally use the N-S method. If you look closely at the picture, you see the ashes are raked toward the front of the stove and to the sides. There is a path in the middle from the front of the firebox to the rear. (between the flames) This allows the air to flow. It also allows the air from the 3 holes at the bottom front of the firebox to flow when the primary air is completly shut. I am careful to keep these holes clear. These holes are not mentioned anywhere in the user manual.

 

[brenndatomu]

I saw that idea and consider it as a way to test.
I still feel that the primary/secondary air ratio is screwy

Ratio could be off...but that is a separate issue from draft that is over specs...and you hafta do what you hafta to do to get that down if you want any kind of efficiency...

 

[Woodcutter Tom]

The splits are pretty skinny. They would be kindling in our stove. They very likely are dry. This goes back to the premise that the wood is outgassing too rapidly due to the small split size.

The thing I don't understand is why doesn't the tube air ignite the gasses in a robust manner prior to being overwhelmed????
Why does the gas get to the front of the stove and get ignited by the primary air as it enters from above the glass?

If I had robust tube flames, and then primary air ignition, it would make more sense to me.

 

[bholler]

The thing I don't understand is why doesn't the tube air ignite the gasses in a robust manner prior to being overwhelmed????
Why does the gas get to the front of the stove and get ignited by the primary air as it enters from above the glass?

If I had robust tube flames, and then primary air ignition, it would make more sense to me.

How long have you just run the stove without making changes or analyzing everything? Do you typically load more that what you show in the pictures? Every time I swap out stoves it takes me about half a season to get it figured out for my setup.

 

[rdust]

The thing I don't understand is why doesn't the tube air ignite the gasses in a robust manner prior to being overwhelmed????
Why does the gas get to the front of the stove and get ignited by the primary air as it enters from above the glass?

If I had robust tube flames, and then primary air ignition, it would make more sense to me.

Don’t get hung up on “tube” flames. If the stove doesn’t create a bunch of unburnt gasses the secondary combustion may not be as obvious. If the chimney is clean I wouldn’t worry about it. I’d echo bholler here and just burn the stove a while without making changes.

 

[Woodcutter Tom]

How long have you just run the stove without making changes or analyzing everything? Do you typically load more that what you show in the pictures? Every time I swap out stoves it takes me about half a season to get it figured out for my setup.

I installed the stove in Nov 2020. It replaced a small 1.2 cubic foot stove that I had for 2 years. That is why I have a lot of small splits.
Just about every time I fire up the stove, I am analyzing what is happening. That does not mean I am fiddling with the air control constantly. I am not chasing the fire. I make changes and observe what happens. Often there are long periods between adjustments. Throughout the winter I was 'learning' the stove.
My general start up is N - S stuffed to the top.

 

[Woodcutter Tom]

The answer to my question.."Am I expecting too much?" is no, I am not. My issue has been massive overdraft. Next year should be better. I outline my results in another thread. 'Primary Air Igniting Gasses'

 

[bholler]

The answer to my question.."Am I expecting too much?" is no, I am not. My issue has been massive overdraft. Next year should be better. I outline my results in another thread. 'Primary Air Igniting Gasses'

I just don't see how you can have a massive overdraft with your chimney height. It just doesn't make any sense at all