It's official: don't burn VERY dry wood!

[branchburner]

Sorry, Dennis, but it's right in the manual (p22) of the new VC 2N1 cat/non-cat hybrid:
http://literature.mhsc.com/vermont_castings/manuals/30005295_Encore_2N1_2.pdf

"Avoid using a full load of very dry wood in the firebox. This may result in continuous very high temperatures in the secondary combustion area and damage the combustor. Wood which has been split and stored under cover for more than 18 months may be considered very dry. If you must burn extra-dry wood, mix it with greener wood for a longer fire and less stress on the combustor."

Oh boy. Gotta get out and cut some green wood for the stove, Ma. Maybe we can soak the lousy stuff we have in the bathtub to get it good enough.

I guess the VC engineers are telling us that the moment our wood is just right, it's no good for their state-of-the-art new stove. My reply: your stove is no good for my wood!

 

[BrowningBAR]

Sorry, Dennis, but it's right in the manual (p22) of the new VC 2N1 cat/non-cat hybrid:
http://literature.mhsc.com/vermont_castings/manuals/30005295_Encore_2N1_2.pdf

"Avoid using a full load of very dry wood in the firebox. This may result in continuous very high temperatures in the secondary combustion area and damage the combustor. Wood which has been split and stored under cover for more than 18 months may be considered very dry. If you must burn extra-dry wood, mix it with greener wood for a longer fire and less stress on the combustor."

Oh boy. Gotta get out and cut some green wood for the stove, Ma. Maybe we can soak the lousy stuff we have in the bathtub to get it good enough.

I guess the VC engineers are telling us that the moment our wood is just right, it's no good for their state-of-the-art new stove. My reply: your stove is no good for my wood!

VC just wants you to gum up and ruin the catalyst sooner so they can bend you over on parts pricing. Genius marketing move.

 

[Todd]

Yeah, I noticed that too, sounds like they are not too confident in the durability of their new stove, no way is 18 months too dry unless you live in a desert.

 

[billb3]

um, mix with 'greener wood', not mix with 'green wood'.

I'd rather see them recommend a smaller charge of extremely dry wood rather than mixing in some less dry wood.
Or maybe a rather stern warning about being careful about flames shooting out the top of the chimney.

I think their advice is sound when not taken out of context.

 

[branchburner]

um, mix with 'greener wood', not mix with 'green wood'.

I'd rather see them recommend a smaller charge of extremely dry wood rather than mixing in some less dry wood.
Or maybe a rather stern warning about being careful about flames shooting out the top of the chimney.

I think their advice is sound when not taken out of context.

All levels of green, greener, and less-green wood are undefined, so there is no context here. It is entirely open to individual intepretation. If they had defined "greener" as wood that was still minimally seasoned, say six months split, that would be different.

They also use the term "moderately dry" and do not define that. Ok, except that virtually every wood dealer sells 4-month old wood as seasoned and 2-month old wood as semi-seasoned. Is this so-called semi-seasoned wood green, or is it "moderately dry"? I say it's green.

They could have mentioned MC%, but instead they chose to define one term only: "very dry" - a term that should really be used to describe kiln-dried lumber, or other wood well under 15% MC. Their 18-month "very dry" wood is generally what most of us consider "dry", maybe 15-20% MC, or perfectly seasoned. If you extrapolate from their definition, they are encouraging the use of wood over 20% MC. That is absurd.

 

[Slow1]

Ahh but on page 23 it says:

"The best hardwood fuels include oak, maple, beech, ash, and hickory that has been split, stacked, and air-dried outside under cover for at least one year.
If hardwood is not available, you can burn softwoods that include tamarack, yellow pine, white pine, Eastern red cedar, fir, and redwood. These should also be properly dried.
Store wood under cover to keep it dry. The longer it is stored, the better heating and fire-viewing performance you will enjoy."

So... Page 22 says "no more than 18 months" but Page 23 says "at least one year" (which last I checked is 12 months) so... I guess you have a 6 month window to burn it... then again Pg 23 says "the longer the better" as well... so what are you to believe here? Sounds like they are saying a bit of everything - some bad editing and confusing/conflicting advice. So - whatever advice you want to believe you can go with (and be wrong when the warranty call comes in).

I actually went to read this as I am curious about this "catalytic/non-cat" stove. It seems to me that the design is simply a cat stove that they will 'allow' you to burn with the damper open (?) - I don't see any burn tubes or such to indicate it does anything special to make it burn clean in non-cat mode. Perhaps they are relying on the refractory to heat up quick and reflect heat on the wood to achieve high temps in the firebox or something.

 

[branchburner]

It seems to me that the design is simply a cat stove that they will 'allow' you to burn with the damper open (?) - I don't see any burn tubes or such to indicate it does anything special to make it burn clean in non-cat mode. Perhaps they are relying on the refractory to heat up quick and reflect heat on the wood to achieve high temps in the firebox or something.

We were speculating about that on the other thread: https://www.hearth.com/econtent/index.php/forums/viewthread/60262/

I think the damper must be closed for smoke burning, whether cat or non-cat. The non-cat mode is a downdraft "everburn" afterburner (like mine) but now made out of a solid refractory instead of the old crumbly stuff (like mine). And the cat is placed right in the afterburner in the back of the stove, which is why they don't want you to burn the stove too hot?

I thought perhaps the cat would help boost temps in the chamber to get a quicker secondary combustion, and then to burn smoke if the secondary stalls. I do believe VC wants the EPA efficiency numbers of the cat, but also want the ease of marketing a non-cat.

I noticed there is even more on dry and green wood on p28. They also state "if you hear a rumbling or roaring noise (like a propane torch), that is a sign the stove is overfiring." Which is interesting, because that noise has often been described in various posts as how to know your afterburner is burning smoke. Confused.

 

[madrone]

Poor choices of words in that manual. Saying that 18 months = too dry is ignoring all the factors that affect seasoning. Kiln dried? Sure, that's too dry for a full load. 18 month oak in a rainy climate? No.

And greener wood? That's inviting people to throw fresh-cut wood in. You can argue semantics, but that's such a vague description.

Give MC% suggestions. Include a moisture meter and thermometer with every stove. Actually, every manufacturer should do that...

 

[Backwoods Savage]

Sorry, Dennis, but it's right in the manual (p22) of the new VC 2N1 cat/non-cat hybrid:
http://literature.mhsc.com/vermont_castings/manuals/30005295_Encore_2N1_2.pdf

"Avoid using a full load of very dry wood in the firebox. This may result in continuous very high temperatures in the secondary combustion area and damage the combustor. Wood which has been split and stored under cover for more than 18 months may be considered very dry. If you must burn extra-dry wood, mix it with greener wood for a longer fire and less stress on the combustor."

Oh boy. Gotta get out and cut some green wood for the stove, Ma. Maybe we can soak the lousy stuff we have in the bathtub to get it good enough.

I guess the VC engineers are telling us that the moment our wood is just right, it's no good for their state-of-the-art new stove. My reply: your stove is no good for my wood!

To me this also proves the theory that when owner's manuals are printed, they are just sort of thrown together without much thought. Some office person just types up a bunch of junk making it sound official and no proof reading is done by someone qualified to do it.

Good case in point is a piece of machinery I recently purchased that had to be assembled. The manual and instructions were the worst documentation I've ever witnessed! I simply do not put a lot of faith in owner's manuals.

 

[soupy1957]

Ok, I'll play the rookie card here:

A) You can burn wood that is green (it's just harder to light, and will produce more resin)
B) Wood that's too old will burn very quickly, and be hotter.
C) Secondaries are made from heat resistant materials that should be able to stand up to
any temps you give them. (I recall from my Heat Treat days, that 1800º was needed to
produce even an annealling of various alloyed metals).

I'm sure SOMEONE will bunk SOMETHING I just said........lol

-Soupy1957

 

[vvvv]

stoves are designed & tested to burn 15%- 20% mc wood. ithinx

 

[blowell]

Hey - have a ton of green wood. Wanna trade!

 

[jdonna]

Wow, what a bunch of non-sense. They should supply a good moisture meter with this stove then to avoid all the confusion. I'm leary of this stove already after my experiences with an oak-wood stove. I think with the refractory in combo with the cat going could be a serious problem with overfiring. Hopefully the casting on the back of that stove is highgrade and an inch thick! Harman gave me the same line that I might be burning too dry of wood, last I checked my supply is ranging between 11-16% moisture.

What is the deal with wood-stocks new design and when is it coming out?

 

[fire_man]

Sorry, Dennis, but it's right in the manual (p22) of the new VC 2N1 cat/non-cat hybrid:
http://literature.mhsc.com/vermont_castings/manuals/30005295_Encore_2N1_2.pdf

"Avoid using a full load of very dry wood in the firebox. This may result in continuous very high temperatures in the secondary combustion area and damage the combustor. Wood which has been split and stored under cover for more than 18 months may be considered very dry. If you must burn extra-dry wood, mix it with greener wood for a longer fire and less stress on the combustor."

Oh boy. Gotta get out and cut some green wood for the stove, Ma. Maybe we can soak the lousy stuff we have in the bathtub to get it good enough.

I guess the VC engineers are telling us that the moment our wood is just right, it's no good for their state-of-the-art new stove. My reply: your stove is no good for my wood!

VC just wants you to gum up and ruin the catalyst sooner so they can bend you over on parts pricing. Genius marketing move.

I think BrowningBAR is on to something. VC can't lose. If something in the stove gets ruined due to high heat, they can blame it on wood that's too dry and void the warranty. If the stove does not burn properly, they can say the wood wasn't dry enough and the customer is at fault. These guys are brilliant. I am imagining a bunch of businessmen standing around with their corporate lawyers dreaming this stuff up, while the Engineers who understand the actual product are helpless. Call me cynical but that's how I see it.

 

[jdonna]

Yea, agreed. They are looking for the best emissions numbers as a sales point and going the route of too dry of wood to limit losses.

 

[BrotherBart]

Let me see here, two thirds of the wood burning world rightly or wrongly believe cat stoves to be a problem. Then we have a significant portion of the downdraft stove owners that perceive down draft stoves to be a problem. With the exception of Hanko, of course.

So let's run out and design a down draft/cat stove.

Say what?

 

[sawzall]

This is all too funny.

 

[Battenkiller]

Ok, I'll play the rookie card here:

A) You can burn wood that is green (it's just harder to light, and will produce more resin)
B) Wood that's too old will burn very quickly, and be hotter.
C) Secondaries are made from heat resistant materials that should be able to stand up to
any temps you give them. (I recall from my Heat Treat days, that 1800º was needed to
produce even an annealling of various alloyed metals).

I'm sure SOMEONE will bunk SOMETHING I just said........lol

OK, I'm in. :lol:

A) Burning wood - dry or wet or just moist - doesn't produce resin. It's either in the wood or it's not. Resin is good. It contains lots more potential heat energy than wood fiber. Woods that are high in resin (conifers, for example) have a higher BTU rating per pound because of this, but they are usually much less dense, so the BTUs per unit volume tend to be lower.

It's not just lighting that is harder. Wet wood is a much better conductor of heat, so it transfers heat into the log easier and lowers wood surface temps. As well, excess water vapor passes through the charcoal on the outside and forms hydrogen gas and carbon monoxide. These reactions are endothermic, so they actually rob the fire of heat. Then there is the dilution of wood gases by the excess water vapor. This is particularly detrimental to modern stoves that need both a high concentration of gases and high enough temperature to ignite these gases.

B) Wood that's too DRY will burn quick and hot, age is irrelevant.

C) I don't know what alloys you were treating, but most carbon steels are fully annealed at temps around 1350-1400ºF. That's about the temp of your coals in your stove. In fact, I anneal old files for tool making by putting them in the stove at night and taking them out in the morning. They go in file hard and come out dead soft.

Sorry, Soupy.... I'm just being a dickhead. :coolsmile:

 

[Beowulf]

[/quote]

C) I don't know what alloys you were treating, but most carbon steels are fully annealed at temps around 1350-1400ºF. That's about the temp of your coals in your stove. In fact, I anneal old files for tool making by putting them in the stove at night and taking them out in the morning. They go in file hard and come out dead soft.

Sorry, Soupy.... I'm just being a dickhead. :coolsmile:

[/quote]


Ok, so now I gotta know... what are you making out of soft old files?

Inquiring minds have a need to know!

 

[branchburner]

Let me see here, two thirds of the wood burning world rightly or wrongly believe cat stoves to be a problem. Then we have a significant portion of the downdraft stove owners that perceive down draft stoves to be a problem. With the exception of Hanko, of course.

So let's run out and design a down draft/cat stove.

Say what?

Maybe it's a real breakthrough, or maybe it is just a design to satisfy the suits. VC has fewer problems with their cats than their non-cats, but as you say, it's hard to interest many customers in catalytic stoves. Most shops steer customers away from cats.

So VC takes their less popular but more functional cat stove and merges it with the more popular concept of a non-cat stove. As long as the cat burns smoke, it really doesn't matter if their downdraft afterburner works well or not, as long as it doesn't work "too well" (as in the past) and turn the stove into a glowing pumpkin. That's why they are discouraging "very dry" wood.

This basically gives them a cat stove they can market as a non-cat. Unless the customer actually wants a cat - then it's a cat. "Why, whatever kind of stove you're looking for, sir, that's what this one is!" I hope I'm wrong.

 

[begreen]

Hope this is not another glow in the back stove, but is sure sounds like it. It may be super clean burning under ideal conditions, but that is just a percent of the home installations out there. More importantly, VC needs designs that are a rugged and reliable as they stoves that first built their reputation. The words "and less stress on the combustor." do not inspire confidence.

 

[branchburner]

One really good sign is that they've gotten rid of the very fragile particle-board type refractory components and put in more solid cast refractory. That seems like a big step forward on the "more rugged" scale.

 

[Slow1]

One really good sign is that they've gotten rid of the very fragile particle-board type refractory components and put in more solid cast refractory. That seems like a big step forward on the "more rugged" scale.

Either that or the original refractory when mated with the cat self destructed so fast in the lab that it couldn't make it through testing so they HAD to upgrade it just to pass testing.

I wonder how the MC on what they are calling "too dry" (18 month air dry under cover) is compared to the standard lab wood used for emissions testing anyway. That stuff is pretty dry isn't it? Granted they don't have to burn 24/7 all season to pass the EPA tests so perhaps for short durations it is ok ?

 

[burleymike]

Almost sounds like an early cat stove where you had to worry about a normal fire killing the cat. A lot of research has been done since the early 1980's about how to make a durable long lasting cat stove. Blaze King has done a fine job of designing a durable cat stove. This thing sounds like it will be a lot of trouble.

 

[soupy1957]

The parts we were annealing were aircraft engine structural parts, although I don't recall the alloy type. I remember driving a heat-shielded fork truck up to a pretty good size "box" (essentially) furnace. We had to monitor the charts on the outside of the furnace, and make sure the temps maintained were 1800º throughout the cycle (a few hours, as I recall). Then I had to get the same fork truck, dress in a heat resistant suit, and go pull the skid of metal parts OUT of the furnace. I'm thinking aluminum alloys were on the skid, but I'm not sure. It's been too many years ago, I guess.

-Soupy1957