Are the amount of flames related to the amount of wood burning?

[ClydesdaleBurner]

OK if my title didn't make sense, what I'm trying to figure out is if I want to get maximum burn time do I want less flame or more? For example if I have a roaring fire going with a firebox full of flames and air control about 1/2 open, is this consuming the wood quicker than if I turn down the air and have only secondaries and small flames on the wood, hence not a firebox full of flames. Obviously my heat output will be less with the latter, but at this point I'm just concerned about maximizing burn time. I would assume less flame equals less wood consuming but I wasn't sure if a full firebox of flames might just be burning the fumes/gases and not the actual wood... I hope this makes sense... Thanks.

 

[BrotherBart]

OK, this thread is going to be fun to watch and I will start it off.

The only thing that ever burns in your stove is fumes and gases.

 

[ClydesdaleBurner]

OK. Good point. But doesn't a secondary burn not actually consume the wood, but burn the gases/smoke from the wood? So do more secondaries burn the wood quicker than having less secondaries?

You might be right this thread could get ugly...

 

[BrotherBart]

All burning is from gases created by the wood getting hot and changing to a gaseous form. The intent of secondary burn technology was to burn the gases up at the top of the firebox that didn't get burned as flames down below. That is why I get a kick out of the run it up and shut the air down school of burning. You can either do that or find an air mix that maintains the stove temp you want with a combination of flames and light show up top. Either way if the piece of wood is over around two hundred and fifty degrees it is turning into combustible gases and one of three things is going to happen. They are either going to burn as flames, burn up top as secondary burn or they are headed up the chimney.

I get the same burn times as the damp it all the way down crowd with a more even heat production curve by finding that mix of flames and secondary that produces the temp I want and letting it roll.

 

[SlyFerret]

I'd be happy just to get my secondaries to kick on. I can't get my stove up to temp. Whatever I thought were secondaries the other day weren't, I don't think.


-SF

 

[BrotherBart]

I'd be happy just to get my secondaries to kick on. I can't get my stove up to temp. Whatever I thought were secondaries the other day weren't, I don't think.


-SF

What? None of this:

 

[SlyFerret]

Sadly, no, not yet.

My stove to is at 460 right now just in front of the flue collar, and about 350 in the center top towards the front of the stove. I can't seem to push it past that yet.

-SF

 

[billb3]

I never had a huge light show in the top, especially all the time.
It would come and go, mostly more of a blue, blue and yellow rolling flame.
Sometimes you could even hear it pop ignite, then be gone.
I just figure if I'm getting a real efficent burn down below, there won't be much gas to ignite.
Which is what I want.

I always used to go outside to look at the exhaust air coming out of my chimney top.
No white or gray and I was happy.

 

[BrotherBart]

Ferret do a "cave burn". Two splits North/South about two inches apart with coals between them and one split laying flat on top of them North/South creating a tunnel right in front of that little primary air "doghouse" in the middle of the front. Leave a couple of inches of space between the back end of the split on top and the back wall of the stove.

The show will begin.

 

[ClydesdaleBurner]

Hey BrotherBart,

You said something that I had noticed... if I burn with 1/2 air and have a lot of flames and secondaries I can get about 3 hr burn time (visible flames), but I noticed that if I turn the air down so as not to smother the fire, but still have smaller secondaries the wood would still be consumed in 3 hrs. I was stumped by this.

So if the fire box is at 255 degrees or 355 degrees does the wood not burn down any quicker? It appears not, but that didn't make sense to me... hey I'm a newbie, what do I know.

 

[jpl1nh]

Ferret do a "cave burn". Two splits North/South about two inches apart with coals between them and one split laying flat on top of them North/South creating a tunnel right in front of that little primary air "doghouse" in the middle of the front. Leave a couple of inches of space between the back end of the split on top and the back wall of the stove.

The show will begin.

Assuming your wood is well seasoned..

 

[BrotherBart]

Hey BrotherBart,

You said something that I had noticed... if I burn with 1/2 air and have a lot of flames and secondaries I can get about 3 hr burn time (visible flames), but I noticed that if I turn the air down so as not to smother the fire, but still have smaller secondaries the wood would still be consumed in 3 hrs. I was stumped by this.

So if the fire box is at 255 degrees or 355 degrees does the wood not burn down any quicker? It appears not, but that didn't make sense to me... hey I'm a newbie, what do I know.

The hotter the firebox and more loosely packed the wood the faster it is going to turn to gases and burn. The more loosely it is packed the faster the individual pieces will get to gasification temperature.

It is usually a thousand degrees or so in there.

 

[Gunner]

All burning is from gases created by the wood getting hot and changing to a gaseous form. The intent of secondary burn technology was to burn the gases up at the top of the firebox that didn't get burned as flames down below. That is why I get a kick out of the run it up and shut the air down school of burning. You can either do that or find an air mix that maintains the stove temp you want with a combination of flames and light show up top. Either way if the piece of wood is over around two hundred and fifty degrees it is turning into combustible gases and one of three things is going to happen. They are either going to burn as flames, burn up top as secondary burn or they are headed up the chimney.

I get the same burn times as the damp it all the way down crowd with a more even heat production curve by finding that mix of flames and secondary that produces the temp I want and letting it roll.

It's all relative as I'm sure you know bart...if you had a 6" liner you may still be in the shut it down group too.

25' of factory built chimney, 18 of it inside the house, when it's less than -10C out the draft will take you arm if your not carefull.

Taking 13 1/2 hrs to go from 750 to 325 stovetop is an even enough curve for me...

 

[begreen]

Taking 13 1/2 hrs to go from 750 to 325 stovetop is an even enough curve for me...

Oh that sounds so nice.... sigh.

 

[colsmith]

I never had a huge light show in the top, especially all the time. [...] I just figure if I’m getting a real efficent burn down below, there won’t be much gas to ignite.
Which is what I want.

This theory doesn't seem right to me. Could just be that my stove is different from yours, billb3. But when I have the most flames lower down I generally have the most secondary burn going on as well. My understanding is that when you have secondary burn your stove is burning the wood (gases) most efficiently and completely. Like Brother Bart I try not to shut down the air too much, although with my stove I can turn the air control all the way down and still have lots of flames (strong draft plus the continuous air flow to the secondary burn tubes) and in fact my indicator for being at a good level is that I still have some secondary burn going on. If it all goes away then I have shut the air down too far and I push it back up a little. Seems to me that if your stove has secondary burn tubes they are meant to be burning stuff up there? I am sure the experts will enlighten us further.

 

[whphel]

All burning is from gases created by the wood getting hot and changing to a gaseous form. The intent of secondary burn technology was to burn the gases up at the top of the firebox that didn't get burned as flames down below. That is why I get a kick out of the run it up and shut the air down school of burning. You can either do that or find an air mix that maintains the stove temp you want with a combination of flames and light show up top.
I get the same burn times as the damp it all the way down crowd with a more even heat production curve by finding that mix of flames and secondary that produces the temp I want and letting it roll.

I have found this to be true for me and I belive what your saying 100% here.

 

[crazy_dan]

My summit likes to sit about an inch from closed all the way down I get 6-8 hours before reloading on 4-6 3"-6" splits lay a couple n/s then the rest e/w on top of the n/s and it works for me. get good secondaries + the desired amount of heat and I get the sleep I want since I only sleep 5-6 hours anyway.
Anyway to answer your question yes the more wood in the more flames or so it seams to me.

 

[BrotherBart]

It's all relative as I'm sure you know bart...if you had a 6" liner you may still be in the shut it down group too.

25' of factory built chimney, 18 of it inside the house, when it's less than -10C out the draft will take you arm if your not carefull.

Taking 13 1/2 hrs to go from 750 to 325 stovetop is an even enough curve for me...

I'm talking about stoves without EBT to modulate primary air input Gunner. With EBT closing it all the way down makes sense since it is going to work to maximize the fuel/air mix. As to chimney diameter, one of the reasons I pulled that six inch out and replaced with 5.5 was monster draft that was wasting heat and a setup that wouldn't allow installation of a key damper.

 

[Jags]

I am in the BroB camp of finding the right mixture of primary air for your stove. After years of running my stove in EVERY darn configuration that can be dreamed up, it doesn't matter how it happens, but if I maintain a 600 deg stove top I get the same burn time, virtually every time, damped down, 10 percent open, 20 percent open, doesn't matter.

 

[jpl1nh]

Great thread, as is this one. I think that the gist of them both is kind of inter-related. https://www.hearth.com/econtent/index.php/forums/viewthread/14921/P0/ IMHO, the answer to the longest burning question is damped down as far as you can. Since oxygen is necessary of combustion (oxidation) the less oxygen, the slower and longer the process. I think the question all of us really want to know is what is the best way to burn our stove for our particular set up. Be Green's question about comparing stoves by burn time per cubic foot or stove space is a great question and as far as I know that info is only available as the anecdotal info we all are attempting to share here. BB's point about burning with the setting that gives decent flames with good secondary really illustrates that optimum place for burning each stove set up has. The challenge for each of us is to learn 3 things and I would argue they are not the same; 1: how to maximize heat output per hour, 2: how to maximize your burn time, and 3: how to burn the most efficiently. It seems to me secondary burn stoves accomplish 1 and 3 better at the same time than cat stoves and cat stoves accomplish 1 and 2 better at the same time than secondary burn stoves. Soapstone simply levels the heat curve of either system.

 

[brooktrout]

I'd be happy just to get my secondaries to kick on. I can't get my stove up to temp. Whatever I thought were secondaries the other day weren't, I don't think.


-SF

What? None of this:

BB- that is a GORGEOUS pic!