PE Summit Secondary Burn

[chris2879]

What do you guys think? Now that I am burning better wood, it seems to be burning much better. The temperature is about 475 at the top right of the door. Below is a 21 second video of the burn. How am I doing, more air, less air? Thanks

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[begreen]

That looks familiar. At that stage I have the air control closed as far as it will go.

 

[chris2879]

If I close down all the way, do you get any flames of the wood or just a few flames here and there in the firebox? I am not sure how far i can choke back. I looked at the chimney with a flash light(dark outside) and it appears to be just steam coming out or a very light colored smoke. It seems like whatever I do, the temp like to be around 475 - 500. I have never gotten it past 520 or so... not sure whats up with that.

 

[Todd]

Looks like a good efficient burn. Kind a hard to know the temps with an insert since you have to put the thermometer above the door. I bet it's hotter on top, maybe remove the top surround and check it?

 

[begreen]

If I close down all the way, do you get any flames of the wood or just a few flames here and there in the firebox? I am not sure how far i can choke back. I looked at the chimney with a flash light(dark outside) and it appears to be just steam coming out or a very light colored smoke. It seems like whatever I do, the temp like to be around 475 - 500. I have never gotten it past 520 or so... not sure whats up with that.

Try it. When our stove is burning like that, I can turn it all the way down. With your good flue, it may be totally possible. The goal is not the light show, it's good heating with less wood consumption. The temps you are reading are not the same as on the stove top. 520 on the face of the stove is respectable. Try closing off the air more, if the wood is good it may actually get hotter.

 

[albertj03]

On my Super 27 I shut the air down all the way as well once I get strong secondaries. I can get the stove top to 600 - 700 degrees no problem.

 

[Hogwildz]

Get that puppy up to 500 and then shut the air all the way down.
Running same insert here with 27' liner. Start at 500 and turn the air all the way down. I cruise at 650 most the burn. I'll let it open full blast until 500-660, the kill the air all the way down. Sometimes it will spike to 750m but always eases back down to 650ish. then slowly tapers down over time. I think you may be cutting it down a lil early, and your wood may be slightly moister than you think.
At right temp, with good wood, it is going to secondary for a while on it's own. With real dry wood, you can shut it all the way back at 400ish and it will climb to cruising temp anyways and obtain secondaries.
Dry wood is real the key. And many think their wood is dry and it may not be as dry as they think. Experiment with cutting back the air at different temps. Find what works best for you & your needs.

 

[DonNC]

noob question here. I looked at the vid and I dont know what you are calling a secondary burn. Ive seen reference to it before on this forum but still do not know what it is.

 

[chris2879]

Hey Hog, where are you measuring your temperature.

I am new to this as well... but I believe the secondary burn is a process that burns the smoke, which improves emissions and generates more heat making the stove more efficient. Correct me if I am misspoken.

 

[begreen]

Last posting, he had two thermometers, located at the door corners. There's a picture of them if you search on his posts.

 

[Hogwildz]

Secondaries refer to the secondary combustion at the top of the stove. IN PE's they are a baffle box with holes. In some other stoves they are baffle tubes with some kind of baffle board on top of them.
Both burn off/combust volatile gases before they exit the stove outlet. Also refers to the light show of flame jets from the bafflers holes.

I mounted my thermos at both corners of the face of the insert, right behind & above both door top corners.

 

[Boozie]

noob question here. I looked at the vid and I dont know what you are calling a secondary burn. Ive seen reference to it before on this forum but still do not know what it is.

I'm so glad you asked Don. I've been wondering what they were talking about also, but had not asked. I still am not sure.

Barb

 

[Pagey]

noob question here. I looked at the vid and I dont know what you are calling a secondary burn. Ive seen reference to it before on this forum but still do not know what it is.

I'm so glad you asked Don. I've been wondering what they were talking about also, but had not asked. I still am not sure.

Barb

Secondary burn refers to the combustion of volatile gases released by the wood. I'm not an expert on combustion, but in my layman's understanding it's something like this: in primary combustion, the wood comes up to about 250F or so until the moisture is evaporated and driven out. Then, with some of the moisture gone and as it gets hotter, it will release volatile gases and droplets of tar. If you get the firebox hot enough AND supply sufficient oxygen to the path of those volatile gases, they'll ignite and burn. This is the much vaunted "secondary combustion". In the video above, it is the flames you see at the top portion of the firebox. In a stove without proper secondary combustion design, those gases would simply go up the flue as smoke and wasted energy. Today's stoves burn these volatile gases using one of two technologies: catalytic and non-catalytic.

http://www.woodheat.org/tips/technique.htm

 

[Boozie]

noob question here. I looked at the vid and I dont know what you are calling a secondary burn. Ive seen reference to it before on this forum but still do not know what it is.

I'm so glad you asked Don. I've been wondering what they were talking about also, but had not asked. I still am not sure.

Barb

Secondary burn refers to the combustion of volatile gases released by the wood. I'm not an expert on combustion, but in my layman's understanding it's something like this: in primary combustion, the wood comes up to about 250F or so until the moisture is evaporated and driven out. Then, with some of the moisture gone and as it gets hotter, it will release volatile gases and droplets of tar. If you get the firebox hot enough AND supply sufficient oxygen to the path of those volatile gases, they'll ignite and burn. This is the much vaunted "secondary combustion". In the video above, it is the flames you see at the top portion of the firebox. In a stove without proper secondary combustion design, those gases would simply go up the flue as smoke and wasted energy. Today's stoves burn these volatile gases using one of two technologies: catalytic and non-catalytic.

http://www.woodheat.org/tips/technique.htm

What a FANTASTIC article. Good reading for all "newbies" such as myself. I think, also, that I now understand "secondary" burn. In fact, I think I observed it last evening.

Thanks again for all the good info.

Barb

 

[Creature]

What a FANTASTIC article. Good reading for all "newbies" such as myself. I think, also, that I now understand "secondary" burn. In fact, I think I observed it last evening.

Thanks again for all the good info.

Barb

Your stove (or that load of wood) might be an exception, but I don't think cat stoves are engineered for secondary burn ("There is no secondary combustion chamber or secondary air tubes" according to the "Catalytic converter EPA rated wood stove" section of: https://www.hearth.com/econtent/ind..._and_new_Wood_stove_technology_for_a_newbie./) .

Maybe some gasses are lighting up before entering the cat ... Then again, I'm a noob too, and I don't have a cat stove (My stove isn't even ready to fire yet).

 

[Boozie]

What a FANTASTIC article. Good reading for all "newbies" such as myself. I think, also, that I now understand "secondary" burn. In fact, I think I observed it last evening.

Thanks again for all the good info.

Barb

Your stove (or that load of wood) might be an exception, but I don't think cat stoves are engineered for secondary burn ("There is no secondary combustion chamber or secondary air tubes" according to the "Catalytic converter EPA rated wood stove" section of: https://www.hearth.com/econtent/ind..._and_new_Wood_stove_technology_for_a_newbie./) .

Maybe some gasses are lighting up before entering the cat ... Then again, I'm a noob too, and I don't have a cat stove (My stove isn't even ready to fire yet).

Will someone clear this up please ...... Do Cat stoves produce a secondary burn?

 

[Pagey]

Secondary combustion just refers to the burning of the gases released by the wood. A cat stove burns these gases by passing them through the catalyst. The catalyst is treated with special metals that allow the smoke to burn at around 500F. In a non-cat stove the firebox needs to be about 1,000-1,100F to reburn the gases. So even though a non-cat stoves puts on a much more active and visible show, a cat stove is still technically taking advantage of secondary combustion.

 

[Boozie]

Secondary combustion just refers to the burning of the gases released by the wood. A cat stove burns these gases by passing them through the catalyst. The catalyst is treated with special metals that allow the smoke to burn at around 500F. In a non-cat stove the firebox needs to be about 1,000-1,100F to reburn the gases. So even though a non-cat stoves puts on a much more active and visible show, a cat stove is still technically taking advantage of secondary combustion.

Thank you. Thank you very much.