Secondary Burn

[Cerran]

Smoke dragon... no glass door.... no view of the fire... no ambiance...
Don't make such a big deal out of my ambiance comment... I can't count how many times I've been told (on this board) how much I'm missing without a glass door and fire view. I can't tell you how many times it's been posted by someone here they wouldn't give up the glass door fire view (ambiance) for any sort of stove. Heck, Del_ went on about it for over a year... on, and on, and on, and on, and on about it. Then, after I got a glass door elitist stove... he became an installation pro and could even diagnose a bad install from hundreds of miles away while lookin' at his keyboard. He must know magic...

Actually it's not glass, it's high temperature ceramic and I find the window to be invaluable when it comes to reloading the stove and when to turn the stove up and down to get the desired output.

 

[Whitespider]

By having an insulated fire box that builds and holds more heat you can turn down your input air to really low levels and still keep the smoke gases burning. ... One of the main advantages of the newer epa stoves is you can turn it down to a low burn rate and still operate at high efficiency...
A smoke dragon dampered down for an all night burn is not burning at 55% efficiency as the more smoke and the more dense the smoke out the flue from a dampered down smoke dragon stove is a visual display of poor efficiency.

First of all, if you think intentionally smolderin' the wood to burn the smoke is operatin' at "high efficiency"... think again‼ There's a reason the EPA testing procedure allows a stove to fail the "low" burn test if it can pass the "medium" and "high" burn test three consecutive times... it's because few, if any, can pass the "low" burn testing.
Second, I don't "damper down" my smoke dragon, I don't adjust anything. I simply open the door, toss in the wood, and slam the door. The thermostat starts the draft blower most mornings around 5:30, a few minutes after I do the mornin' loadin'... runs for anywhere from ½ to 1½ hours depending on how cold it is outside. Sometimes it will start-up after dark for a few minutes, maybe once during the day if it's really cold out, and on a real nasty night I hear it kick on 'round 2-3:00 in the morning for a bit. Just for FYI, I usually turn in 'round 8:30 PM (give-or-take) so I load the smoke dragon about 8:00, and forget it until 5:00 when I roll out (9 hours)... the thermostat does auto lower itself from 70° to 66° at 9:00 PM.
Third, my smoke dragon doesn't "smoke", except for a couple minutes immediately after loading... actually, my elitist stove smokes more after loading than the smoke dragon does.

...every 8 hours or so I just open the air control up ,stir the coals a little ,load the stove up,shut the air almost all the way closed in about 15 minutes then repeat...

I just open the door every 6-12 hours (depending), toss some wood in, slam the door... done‼

I find the glass to be invaluable when it comes... to when to turn the stove up and down to get the desired output.

Hmmmm.... that must suck for you?? I never have to fiddle with anything‼

Yes, and this is the crux of the problem - fossil fuel heating system expectations.
Wood stoves don't do well in any of those things. All of them have a heat output that varies over time, and cannot be throttled down very far without combustion issues. It's tough to match the BTU/hr of a fossil fuel burner system.

You must mean "elitist" wood stoves don't do well in any of those things... 'cause I've never had problems meeting my expectations with any of my smoke dragons. It's simple... those are my expectations... that's what I've always had, that's what I want (shrug)... b'sides, burnin' the stuff should be the easy part‼
Like I said, elitist stoves ain't the be-all-to-end-all some of these guys think they are... they ain't always the right choice for all applications (or expectations, I guess)... and you just made my point for me.
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[Cerran]

Hmmmm.... that must suck for you?? I never have to fiddle with anything‼
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You don't have to "fiddle" with anything because you have so much heat loss in your house. Part of owning a wood stove is setting the output based on the burn stage of your wood. I heat my entire house on ~3 Cord a year (give or take half a cord).

 

[Whitespider]

You don't have to "fiddle" with anything because you have so much heat loss in your house. Part of owning a wood stove is setting the output based on the burn stage of your wood.

You don't have a clue at all... do you??

THERE AIN'T ANYTHING TO ADJUST ON MY SMOKE DRAGON‼ ZILCH‼ ZIP‼ NOTHING‼ NADA‼

You regulate the standby heat output by the quantity and quality of fuel you load it with. On a warm(ish) day ya' just toss in a couple or three splits of elm or ash, on a cold-azz night ya' toss in more, on a really nasty-azz windy night ya' load some oak in there with it. The idea is to load it just a tad light, so it slowly loses ground in standby as the circulation blower cycles on and off from air-jacket temperature. When the temp in the house drops ½° below set point (digital t-stat), the draft blower kicks in and brings the fire roaring to life until the house temperature raises to ½° above set point (10 or 15 minutes depending on the fuel load). At that point the draft blower stops, the fire goes back into standby mode with just enough heat to cycle the circulation blower on for a couple minutes, every 15-20 minutes or so. That circulation keeps the house at a steady even temperature... plus it pulls the return air through a furnace filter to keep everything clean and dust free. It may be hours before the draft blower kicks on again, or even a full day... often the only time it runs is for a short time at 5:30 AM when set point automatically goes from 66° to 70°.

I'll say it again... the idea is to load it just a tad light, so it slowly loses ground in standby, and let the draft blower catch the furnace up with demand (if needed). If I loaded that thing to the gills during the day, even a -10° day... it would turn our house into a sauna just idling in standby mode. Most days I load the thing in the morning when I roll out at 5:00 Am, the draft blower starts up 5:30 to raise the temp from 66° to 70°... and it don't get loaded again until after dark that night (if temps are in single digits or lower the wife might toss in 3 or 4 splits mid-afternoon).

70° all day long (66° at night), in every room, every day, no matter what the weather... I don't adjust crap, 'cause there ain't crap to adjust.

Part of owning a wood stove is setting the output based on the burn stage of your wood... my azz‼
Part of owning an elitist stove is fiddling with the damn thing... I want no part of it. I don't even haf'ta "clean" the ashes out'a mine, I just pull the drawer out, dump, and slide the drawer back in... and I can do that no matter what stage the fire is in.

Makin' firewood should be the hard part... burnin' it should be the easy part... if makin' the burnin' part the easy part also means burnin a little more wood, so-be-it, it's worth every friggin' stick‼
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[Whitespider]

Controlling a smoke dragon has very little to do with "adjusting" it... it's mostly about how you load it.
If ya' have a clue, if ya' know what you're doin', ya' never need to "adjust" anything... and it won't "smoke" neither‼
And... if ya' have a clue, if ya' know what you're doin'... they burn a whole lot more efficiently than you imagine.
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[Cerran]

Controlling a smoke dragon has very little to do with "adjusting" it... it's mostly about how you load it.
If ya' have a clue, if ya' know what you're doin', ya' never need to "adjust" anything... and it won't "smoke" neither‼
And... if ya' have a clue, if ya' know what you're doin'... they burn a whole lot more efficiently than you imagine.
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So you are trading ability to control heat output with adjustments (more finite control) with a control method (adjust wood supply) that is grossly inaccurate in comparison.

You're basically making the claim that somehow making 2 maybe 3 adjustments over the course of 8 hours is a deal breaker which simply doesn't make any sense. Not to mention you have automatic control which makes air adjustments for you.

 

[1project2many]

As usual, you're full of $h!t Del. My elitist stove has been installed in the shop for well over a year now... installed exactly per manufacturer's specifications. There has be zero... absolutely zero improvement. If you're gonna' try and add something to the discussion... at least try and add something of relative value instead of your self-serving bu!!$h!t.

No... at least not that supports your claim of better heating efficiency (except through your own conjecture).

See... I believe too often in discussion such as this, too much emphasis is placed on fuel efficiency as the be-all-to-end-all. Sure, there are times when fuel efficiency is a consideration; such as lookin' to buy a car for my teenage daughter for drivin' back and forth to work. But if I'm lookin' for a truck to pull my stock trailer across the county horsepower comes way before fuel efficiency.

Now if I'm lookin' to put a stove in my cozy little den for a little ambiance and supplemental heat... and especially if I buy my firewood, fuel efficiency would be a consideration. But if I'm lookin' to heat my entire drafty, uninsulated, old farm house when it's -20° and blowin'... horsepower (i.e., BTU output per hour) is the only friggin' consideration. (And don't talk at me about insulation... we're talking about the difference in applications.)

I guarantee when high heat, really high heat, hour after hour after hour after hour is required, a smoke dragon pullin' air up through the fire from the bottom is gonna' outperform and elitist stove every friggin' time. Hang the friggin' fuel consumption, more horsepower requires more fuel. And it ain't linear, more horsepower necessarily means lower fuel efficiency (even in your elitist stove)... always has been that way, always will be.

What is, or isn't, "better" ain't as cut 'n' dried as you make it out to be... it's never been as simple as a few "efficiency" numbers.
I'm not the one in denial here, I fully concede to the points from the "other side"... it's the "other side" that (usually) refuses to concede any points from this side.
And that's why I call them "elitist stoves"... it friggin' fits.
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You're off the mark with the engine hp/fuel efficiency comments. I can give good of examples of low HP old engines using significantly greater amounts of fuel than modern counterparts to do less work and produce less power. I can also give examples of how properly matching engine displacement and power range to vehicle and load can improve overall efficiency and reduce fuel consumption over time. Poor analogy.

Lots to say about why reburn / secondary burn works well but likely old news. I'm using at least 30% less wood with this stove than the old one I removed and we feel warmer than before. I'll stand by that number. It's not magic. It's because more of the HC's released from the wood are able to burn. Heat regulation is made easier by using varying size pieces of wood and varied species, too. How ya load it, just like an old stove. Part number stickers on single wall pipe attached to stove didn't turn brown for over two years after install. No high flue temps there. Ingrained thinking to fill firebox with high density wood and large pieces will result in high output that's harder to regulate. Fault of operator. I (over)load stove around 12:00 pm with large piece and start secondary burn, house temp rises and drops during sleep, we wake to comfortable temperature. Sucks to get up at 12:00 to reload, though.

I have installed a smaller reburner in the barn so I'll be watching that one. Stove is grossly undersized, barn is grossly uninsulated. Changes to come in that area. Sounds closer to the drafty farmhouse application you're describing than the stove in my house. Will it fill with coals and not be useful to make good heat? It does coal up sometimes but I haven't found it running out of heat. I switch to light species or punky stuff that burns faster to keep secondary burn going while coals burn down some. Not too hard for me to work with that. But I'll watch over time. It doesn't make as much heat as the barrel stove in the old shop, but it's also about 1/3 the size of the old stove and the barn has much greater heat loss.

I don't believe it's stove size, I don't believe it's bad installs. I believe it's real simple, the design can't keep up with demand when heat loss is high...

Now that's just backward. You're saying that no matter how large the stove, it can't possibly provide enough heat because of the design. That's counter to common sense and practical experience.

Part of owning an elitist stove is fiddling with the damn thing... I want no part of it.

FWIW there's no "fiddling" with either of my stoves. My wife can run them successfully, and I'd say she's more of a bassist than a fiddler. There are downsides and I've spoken about them before. Fiddling is not one of them.

 

[Whitespider]

So you are trading ability to control heat output with adjustments (more finite control) with a control method (adjust wood supply) that is grossly inaccurate in comparison.

If it's so damn "inaccurate", why doesn't my house vary in temperature no matter the weather??
Like I said, if ya' have a clue, if ya' know what you're doin'...

You're basically making the claim that somehow making 2 maybe 3 adjustments over the course of three hours is a deal breaker which simply doesn't make any sense.

Why doesn't it make sense?? That's silly?? The firebox is in the basement, I'm not always home, even if I'm home I'm not always in the house, and I turn in 'round 8:30... not haf'in to fiddle with it makes perfect sense to me. In fact, it makes one he!!-of a-lot of sense to me‼

Not to mention you have automatic control which makes air adjustments for you.

Only if heat demand requests it, not because the firebox requires it "based on the burn stage of your wood" (as you put it)... those are two very different things.
My previous (homemade) smoke dragon(s) didn't have any automatic air adjustment, but the circulation blower was automatic. They were a bit trickery to load and run... meaning the learning curve took a little longer and it was easier to make a mistake and overload, especially early in the season. Those used a flue damper for control... you opened it fully to load the thing (or flame bellowed out the door), and then you closed it based on expected heat demand/fuel load/ambient conditions. Once you caught-on, it became second nature... no big deal.
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[Cerran]

Only if heat demand requests it, not because the firebox requires it "based on the burn stage of your wood" (as you put it)... those are two very different things.
My previous (homemade) smoke dragon(s) didn't have any automatic air adjustment, but the circulation blower was automatic. They were a bit trickery to load and run... meaning the learning curve took a little longer and it was easier to make a mistake and overload, especially early in the season. Those used a flue damper for control... you opened it fully to load the thing (or flame bellowed out the door), and then you closed it based on expected heat demand/fuel load/ambient conditions. Once you caught-on, it became second nature... no big deal.

Which is no different than changing the primary air control on a modern stove. There are stoves that have somewhat automatic control based on a set temp .

Why doesn't it make sense?? That's silly?? The firebox is in the basement, I'm not always home, even if I'm home I'm not always in the house, and I turn in 'round 8:30... not haf'in to fiddle with it makes perfect sense to me. In fact, it makes one he!!-of a-lot of sense to me‼

So you're comparing a wood furnace to a room heater. That doesn't make sense. Have you tried one of the newer wood furnaces?

If it's so damn "inaccurate", why doesn't my house vary in temperature no matter the weather??
Like I said, if ya' have a clue, if ya' know what you're doin'...

Because you have gotten used to your setup and know what your house needs with good precision. It doesn't make the method you are using any more accurate. It's the difference between precision and accuracy.

 

[Whitespider]

You're off the mark with the engine hp/fuel efficiency comments. I can give good of examples of low HP old engines... I can also give examples of how properly matching engine displacement and power range... Poor analogy.

Oh... stop it
Don't over analyze... it ain't a poor analogy.
A 4-cyl Escort engine ain't gonna' pull my stock trailer. And with any engine, and all else remains the same, more fuel means more power.
But that wasn't my point... my point was the fuel to to power ratio ain't linear as power is increased.

Now that's just backward. You're saying that no matter how large the stove...

They only make 'em so large in the elitist configuration my friend... only so large.

FWIW there's no "fiddling" with either of my stoves.

Good‼
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[Cerran]

They only make 'em so large in the elitist configuration my friend... only so large.

Actually industrial energy systems using the same basic concepts of an EPA wood stove have been in use for more than 20 years and I've worked on units up to 150 MMBtu/hr. Like it or not, the technology is built on a sound basis from a combustion standpoint.

 

[Chris-PA]

I don't adjust crap, 'cause there ain't crap to adjust

You have an electric control switching between smoldering and a forced draft wood incinerator. No wonder you have no coals. And you claim no adjustments? My stove does not require an automatic control system to make it work - in fact it works with no power at all, and in practice we rarely make an adjustment after the initial setting. None. So in fact your system requires continual active adjustment where mine does not.

In smolder mode it will create plenty of particulates, sending energy up the stack in the form of carbon molecules. In forced draft you'll be sending lots of heat energy up the stack directly, but the total output will be high.

All this time it turns out that you've been comparing secondary combustion wood stoves to your "smoke dragon" when it isn't even a wood stove at all, it is a forced draft wood furnace. I bet the energy output rate of that thing is double what your little stove could do even at maximum secondary combustion.

Essentially the entire conversation has been irrelevant.

 

[Whitespider]

So you're comparing a wood furnace to a room heater. That doesn't make sense. Have you tried one of the newer wood furnaces?

I ain't tryin' to heat a room.. I'm heating a home.
If it don't burn on a coal grate, if the air don't come in under said grate, and if the ashes don't fall through said grate... I ain't interested in "trying" it (maybe if someone gave me one). Fool me once...

You have an electric control switching between smoldering and a forced draft wood incinerator.
All this time it turns out that you've been comparing secondary combustion wood stoves to your "smoke dragon" when it isn't even a wood stove at all...

Don't act so incredulous... how could you not know what I'm talkin' 'bout?? How many friggin' threads have there been??
And so what?? It's a firebox ain't it?? A smoke dragon firebox.

Oh... and it don't "smolder"‼
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[Cerran]

I ain't tryin' to heat a room.. I'm heating a home.
If it don't burn on a coal grate, if the air don't come in under said grate, and if the ashes don't fall through said grate... I ain't interested in "trying" it (maybe if someone gave me one). Fool me once...

Which was my point, you are comparing something that was obviously ill suited to the application (your PE stove) from a sizing perspective to something completely different.

For the size application of a room heater, grates are not going to be a benefit and in fact will be a detriment to the type of combustion taking place. (for a reburn or cat wood stove)

 

[Locust Cutter]

I'd like to know how people are getting 6-8+hr burn time with an EPA box... If I'm lucky and running Hedge, I might get about 4hrs. usually its 2-3 before the coals have settled down and aren't glowing as brightly. It's even less if it's windy outside.

 

[Cerran]

I'd like to know how people are getting 6-8+hr burn time with an EPA box... If I'm lucky and running Hedge, I might get about 4hrs. usually its 2-3 before the coals have settled down and aren't glowing as brightly. It's even less if it's windy outside.

I regularly get 7-10 hour burn times with my Quad 3100i. Usable heat output is about 6-9 hours of that depending on the outside temp. It really sounds like your stove is undersized for your application if you're having that much trouble.

 

[Locust Cutter]

Well, it's the biggest one PE makes. And those burn times are either completely damped down or within an inch f it depending on the wood and it's air req't. There weren't many bigger options outside of a Mansfield Equinox.

 

[Cerran]

Well, it's the biggest one PE makes. And those burn times are either completely damped down or within an inch f it depending on the wood and it's air req't. There weren't many bigger options outside of a Mansfield Equinox.

And you're not baking yourself out of your house? How big of a space are you trying to heat?

 

[Whitespider]

Which was my point, you are comparing something that was obviously ill suited to the application (your PE stove) from a sizing perspective to something completely different.

Actually I'm not...
My previous "furnace" was a modified smoke dragon "stove"... basically, I built a plenum around it and forced air through it. It worked just fine to heat my home for years... it burned on a grate. I did the same modification with the PE and it failed miserably. The fireboxes were the same size (actually the PE was just a touch bigger), although different in shape... the smoke dragon was a little longer, but narrower. From a size perspective they were as close to identical as two (different) stoves can be. Sure, my current "furnace" outperforms my old (converted) one... but my old converted one was 10-times more effective than the converted PE. My comparisons are based more in that than anything else.

And, by-the-way, I converted the PE back into a stove before moving it into the shop... it didn't change the burning characteristics one iota.

I'd like to know how people are getting 6-8+hr burn time with an EPA box... If I'm lucky and running Hedge, I might get about 4hrs. usually its 2-3 before the coals have settled down and aren't glowing as brightly. It's even less if it's windy outside.

L-O-L ‼
It has to be at least 45° outside before I can get 3 good heating hours out'a mine... you're doin' better than I've ever got.
But mine ain't the biggest PE... there's one a little larger (that would be yours).
Heck, even at 40° it wastes more wood in coals thrown out than my current furnace burns‼
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[Chris-PA]

Don't act so incredulous... how could you not know what I'm talkin' 'bout?? How many friggin' threads have there been??
And so what?? It's a firebox ain't it?? A smoke dragon firebox.

Oh... and it don't "smolder"‼

Perhaps because once again you insist on using terms that already have meanings in your own unique way - in this case not a technical term but the slang "smoke dragon" which is not what you have. My brother in law has a pellet stove, which is also not a wood stove. My dad actually has a smoke dragon - it's an old wood stove with no secondary combustion system. It has no fan forcing air through the firebox. It has a heat output profile that rises, peaks and falls, like mine does but with a different shape without the secondary burn.

Your device has a fairly constant output rate until it runs out of wood, as there is a blower forcing air through the burning wood and an active control system that can do that for longer times as the wood load burns down. And in between the air is closed down, just like I could do with my stove if I didn't need the heat or care how much junk it put out.

All this complaining about coals in comparison to a stove type you don't even have, and using a fan forced system that cannot possibly accumulate coals as a reference. Simply nonsense. Why on earth you ever thought a stove could compare to a system with a blower forcing air through the fire is beyond me.

Comparing a secondary combustion stove to a forced draft furnace is not at all the same as comparing one to an earlier stove design. Having used a smoke dragon I often wondered why your experiences seemed so different from my revollection. It's because you were describing something completely different.