Defiant NC Everburn Doesn't engage

[dtabor]

If the lowest my winter temps got was 40, Id not have to have a wood stove!! 40's all winter would be balmy!

As Ive said with my NC Defiant. Im happy with it thus far except that damper lever issue which is now resolved, but Im reserving my final judgement until after we've had "real" winter. As far as I can tell, mine is working ok. Ive used the tips Elk has given. But, then again, I wouldnt really know if it WASNT working ok. Once I engage, I hear the rumble and my top temps seem to hover btw 5-600 or so until it gets burned down. Thats with the air control fully open.

 

[dtabor]

Agreed on the position of the holes as well. You cant have the holes in that location AND leave a bit of ash in the bottom as other posts have recommended. Just wont cut it.

 

[swestall]

When I was able to get the secondary burn engaged I found it kept the griddle temp up to 5-600 as well. What was not "good" was the stack temp. which was hovering around 350-425 at 3 feet up the pipe. That was my best/cleanest burn though. Yes, real winter would be nice for this, but for plowing, I can wait.

 

[webbie]

dt, if it was not working, you stack temp would be really low after you engage damper. Also, lots of smoke and smell would be constantly coming out the chimney......

Sw, the Acclaim had similar air holes, but they never did negatively affect the burn. So perhaps our eyes can fool us....wood ash just might be light enough to allow the air to pass though.

In fact, I once visited an Acclaim customer who had let the ash buildup get to 6-8", and that thing was still working to a pretty good degree!

OK, now this is complete speculation, but I did hear that when Harman was testing their downdraft model, they saw that it passed EPA easily, but did not work as well with cord wood. So they made a decision to add additional air holes in various places, even through it DOUBLED the GPH results. The reason was for "real world" performance....

Travis probably knows a lot about all this, but I would assume those are trade secrets. After all, why share? If the stove(s) work well, that is all that is needed.

Now don't go drilling extra holes in that VC or CDW!

 

[elkimmeg]

Air is suppose to be injected threw those holes, the only way the could be plugged is while cleaning ash is pushed up against them

This has gone long enough I'll call VC and ask for answers Sorry Criag but enough is enough.

 

[swestall]

Funny you would say don't go drilling holes, that was exactly my first reaction: actually to enlarge the holes a little so more air could get through them to make up for the ones on the front block that are below the ash level. But, my concern is that could create a run away secondary burn. Not that I would mind a bit hotter burn. I have thoght of ordering a spare base block for the Defiant and drilling out the one in place just to see what happens. It might be too much to think but if I were the engineer on this, I'd have calculated the airflow and placed the siphon holes so it would be constant. You may have stumbled on what could be a wonderful fix for VC: just provide stove owners with a corrected secondary air supply siphon block.... We'll have to see. Before I do that, it needs to get colder because we all start the 24/7 routine when that happens and that alone will change things alot. Should be an intersting one to follow though.

 

[webbie]

A lot of updraft non-cats have constant (fixed) secondary air flow, so this in itself is common practice.

Elk - call whomever you like - but the "real" answers will not be with VC, but only in the field after a year or two. Proof is in the pudding as we all like to say. Who knows, VC may even fiddle with the holes as the years go by - it is typical to continuously improve such things as feedback comes in.

 

[tradergordo]

I have two unrelated thoughts here.

1) Those holes you are talking about toward the back of the stove - they aren't there to supply secondary air! Quite the opposite actually, in fact if they were supplying secondary air they wouldn't be getting clogged up. Combustion air for the primary firebox actually comes from the front/top of the stove. Those holes at the back are there to deliver gasified wood to the secondary combustion chambers. If you add your own shields over them, they won't do what they were intended to do. That said, plugging some of those holes might actually improve performance, who knows? It could force a more concentrated, and hotter supply of gasified wood though the main opening (i.e. the throat).


2) To illustrate a point about emissions vs. a stove owners perceptions, look at the Omni study if you have some time. Do a search on "defiant" to pull out everything on the person with the Vermont Castings Defiant Encore Catalytic stove (EPA Phase II certified to burn at 1.6 g/hr).

Actual quotes from the study: "The Vermont Castings Defiant Encore (Appendix A, Photograph 31) is in good working
condition, including the door gaskets and refractory elements."

"The owners indicated that they are happy with the stove."

During the first of two full week study periods with this stove, it was burning 98% of the time. By most measures, it SEEMED to be burning great, in fact this person used nearly half the wood that some of the other stoves burning full time consumed. The average indoor temp was a cozy 71 degrees F. And yet the emission rate was a horrible 23 g/hr! (remember its certification value is 1.6 g/hr)

So the owner is happy, their house is warm, they aren't using that much wood, and yet they are polluting like crazy and not getting anywhere near the EPA certification number on emissions. So just because someone says they are happy with their stove, or they are heating their house fine, that doesn't necessarily mean they are burning clean. And for what its worth, the average non-cat EPA phase II stove burns cleaner over time and under real world conditions than the average cat stove in multiple studies that I've seen so far. But perhaps these everburn stoves will change all that

 

[Rob From Wisconsin]

Cutting through all the "variables".....

Like was previously mentioned, is Everburn "draft-sensative"?
Is it too early (not cold enough) to generate the sufficient draft that is required??
Does it operate better w/ a metal chimney than a masonry?

Also, it sounds like users w/ the "larger" Everburn units are voicing problems.
How about the two smaller Dutchwest units??

I'd like to know.....

Rob

 

[webbie]

Trader, perhaps I am misunderstanding, but are you saying that those holes push toward the rear of the stove as opposed to pull from the rear and inject air at the bottom of the throat? If so, I think that is wrong....let me dig up the patent on similar stoves...

Ok, look at google patents - 4856491

See enclosed - notice #96 in the drawing.

BTW, this drawing also shows the sloping grate which the Acclaim has/had and why the coals are easier to build up in such a design.

 

[elkimmeg]

in fact this person used nearly half the wood that some of the other stoves burning full time consumed

yet they are polluting like crazy and not getting anywhere near the EPA certification number on emissions.

so reading from trader quoted study, this defies all logic if they are burning 1/2 less wood than how can they be polluting more than other stoves burning twice as much?

Isn't efficiency also measured in the amount of wood burnt? Boy doe this need explaining

 

[tradergordo]

No we are talking about a different set of holes. Maybe I'm just confused about what part the original poster is talking about. That said, if he was talking about #96 in your diagram I don't see how that could EVER get plugged with ash - it does nothing but suck air into the secondary combustion chamber. Only way I can think of that it would get clogged was if the flue gasses were running in reverse (a very serious problem indeed). Although it does seem a little strange that at least the way it looks in that diagram, ash is heaped right up against it. The Dutchwest design is a lot different than that diagram, the coal bed isn't actually supposed to extend INTO the secondary burn chamber (I would think it would be a maintenance nightmare if it did as you'd have to clean ash out of there continuously).

Trader, perhaps I am misunderstanding, but are you saying that those holes push toward the rear of the stove as opposed to pull from the rear and inject air at the bottom of the throat? If so, I think that is wrong....let me dig up the patent on similar stoves...

Ok, look at google patents - 4856491

See enclosed - notice #96 in the drawing.

BTW, this drawing also shows the sloping grate which the Acclaim has/had and why the coals are easier to build up in such a design.

 

[Todd]

When I was able to get the secondary burn engaged I found it kept the griddle temp up to 5-600 as well. What was not "good" was the stack temp. which was hovering around 350-425 at 3 feet up the pipe. That was my best/cleanest burn though. Yes, real winter would be nice for this, but for plowing, I can wait.

If your stove top is 5-600 and at the same time your stove pipe is 350-425 I fail to see why that is bad. The pipe temp should be less than the stove temp. That tells me it's working correctly. More heat in the stove verses the pipe equals high efficiency. Every EPA stove I've owned whether cat or non cat acted that way.

 

[Todd]

in fact this person used nearly half the wood that some of the other stoves burning full time consumed

yet they are polluting like crazy and not getting anywhere near the EPA certification number on emissions.

so reading from trader quoted study, this defies all logic if they are burning 1/2 less wood than how can they be polluting more than other stoves burning twice as much?

Isn't efficiency also measured in the amount of wood burnt? Boy doe this need explaining

There could be many reasons for going through 1/2 the wood. They might not be at temp when egaging the cat or the cat was dead and produced a smouldering fire but enough heat to keep them warm enough. Kind of like running an old airtight. Was the stove oversized for the house? Wet wood? Type of wood?

 

[Gunner]

If the lowest my winter temps got was 40, Id not have to have a wood stove!! 40's all winter would be balmy!

As Ive said with my NC Defiant. Im happy with it thus far except that damper lever issue which is now resolved, but Im reserving my final judgement until after we've had "real" winter. As far as I can tell, mine is working ok. Ive used the tips Elk has given. But, then again, I wouldnt really know if it WASNT working ok. Once I engage, I hear the rumble and my top temps seem to hover btw 5-600 or so until it gets burned down. Thats with the air control fully open.

Was the fully open a typo?

Should not have to keep the air fully open to maintain 5-600 stovetop. Something is wrong, wood, draft etc.

Once you get to 600 you should be able to cut it back most of the way and maintain temps. Fully open for extended periods will overfire most any stove with good draft and dry wood, the fact that yours is only getting as hot as 600 indicates something is wrong.

What are your burn times like?

 

[webbie]

No we are talking about a different set of holes. Maybe I'm just confused about what part the original poster is talking about. That said, if he was talking about #96 in your diagram I don't see how that could EVER get plugged with ash - it does nothing but suck air into the secondary combustion chamber. Only way I can think of that it would get clogged was if the flue gasses were running in reverse (a very serious problem indeed). Although it does seem a little strange that at least the way it looks in that diagram, ash is heaped right up against it. The Dutchwest design is a lot different than that diagram, the coal bed isn't actually supposed to extend INTO the secondary burn chamber (I would think it would be a maintenance nightmare if it did as you'd have to clean ash out of there continuously).

In the acclaim (that diagram) the ash and coals certainly did build up right against and over the air inlets - and I can see how folks looking at them would assume that they become clogged because of that. But they didn't, again because of how might wood ash is...or for whatever reason.

I'll have to study some of the other designs closer in person......or in stove, whichever it might be.

This air is what fuels the secondary burn - by adding air just where you need more (the other air is consumed earlier in the fire)

 

[Gooserider]

IIRC the Omni study, the Defiant they were looking at was burning some of the wettest wood in the entire study, and had NOT been serviced or cleaned in several years, including running a very elderly cat. The gaskets may have been OK, but the rest of the stove was a good example of "how not to maintain a good burning stove"

Gooserider

 

[elkimmeg]

why do we keep going back to such an unscientific bogus study? Total lack of controls no control of wood moisture no stove condition report. Presented by a lab that lost its certification
for falsifying results. Now does that sound like a study that holds a lot of credence? What the hell did BI members infiltrate our forum?

 

[webbie]

Wait, Elk - you quoted Omni about the cleanest stoves! You cannot have it both ways.....
http://www.omni-environmental.com/cvhouck_publications.html

Omni is very highly regarded in the field, and a lot of people (including some who worked at VC!) were "in" on that study. The EPA and other government agencies also work with Omni on stuff like this.

It is the ONLY scientific field study which has been done in the last decade, so I wouldn't call it bogus. It showed what we all knew for a long time, that stoves in the field perform vastly different than in the lab.

I would like there to be many more studies like this, but it is very expensive to set up a complete EPA lab in a persons house!

Elk, the study clearly says what it is and what it is not. To me it means nothing about brands, but rather that stoves and users/chimneys have a long way to go before they REALLY perform in the best way possible.

 

[TMonter]

why do we keep going back to such an unscientific bogus study? Total lack of controls no control of wood moisture no stove condition report. Presented by a lab that lost its certification for falsifying results. Now does that sound like a study that holds a lot of credence? What the hell did BI members infiltrate our forum?

Unscientific? Maybe, but it also underscores the need for a user friendly system (Or more training) which as a whole the non-cat stoves seem to be better for.

so reading from trader quoted study, this defies all logic if they are burning 1/2 less wood than how can they be polluting more than other stoves burning twice as much?

Actually it doesn't defy logic. When stoves are turned down further they tend to do worse on emissions. This is also true of industrial boilers. Solid fuel appliances have lousy turndown compared to liquid or gas ones. This is simply the nature of the beast.

 

[dtabor]

Gunner, Nope, not a typo, but I dont sit there and watch it either. Once I turn the air down, I leave to do other things or go to bed. Also the fact that its not really cold here yet but I believe my draft is fine, only way to know for sure is to have it measured I guess. The chimney is a 1 piece 8" SS, 25' up thru an existing brick chimney in center of house and insulated.

Ive said before that Im not making any judgements on this thing until we get cold weather and Im burning 24/7. Then if there are issues, the dealer/installer will be at my place fixing things. Such is the reason I paid so much to have THEM do it!! Accountability.

 

[tradergordo]

Elk - I would love to see a new, bigger, and better study. You are right, they didn't set careful enough controls. The odd thing is that the people running the study were the ones that actually supplied the wood to the participants, they also carefully measured the weight and moisture content of all wood burned. I guess they just couldn't find a consistent supply? Don't know. But at least they documented all of this. But my point in bringing up the study was simply to point out that people can be perfectly happy with their stoves, and heat the houses just fine, all while being totally clueless about their emissions. Nothing more, nothing less.

The point is that hearing about people that are happy with a particular stove shouldn't be evidence that they are getting consistent clean burns, especially when so many have reported problems in this regard and no one with a stove of the design in question has posted on the forum that they are able to achieve consistent, hassle free, clean burns.

 

[webbie]

Actually it doesn't defy logic. When stoves are turned down further they tend to do worse on emissions. This is also true of industrial boilers. Solid fuel appliances have lousy turndown compared to liquid or gas ones. This is simply the nature of the beast.

Interestingly enough, the above it true ONLY in the field. In the lab, stoves produce less particulates (GPH) if they top at a LOW output, because less wood = less particulates! Same reason is why OWB's were tested and ended up almost as clean as EPA stoves.....because it was adjusted for the GPH per KILO of wood burned.

The good news is this - the renewed popularity of wood burning is going to advance stoves up a notch. As I said before, the last two decades were a down market for wood stoves, and therefore there was not too much competition nor as much R&D;as their could have been. Now the manufacturers are looking a little closer.

 

[BrotherBart]

Observation about this "Everburn" type technology. I stopped by the local Harman dealer's place yesterday. Noticed that the secondary combustion chamber on the Exception stove and insert are cast iron while the new TL-3000 uses the ceramic refractory stuff.

 

[swestall]

Hello All, I've been out of town for a few days, when I got home my wife said, "I'm freezing, light the stove". So I did. It would be nice if the Defiant CAT/NC had a nice diagram like the Acclaim. They are similar, but, the stove bottom grate is level and the Shoe refractory (where the holes are) and secondary burn Fireback opening are also at the bottom of the stove. It seems to me that ash is going to get into these siphon holes over time and they are going to need attention, especially the ones directly on the bottom/front of the shoe. I am trying to get the stovetop and flue temp up to 600 with some coals in front of the shoe prior to closing the damper; last time that seemed to work. There is no visible smoke out the stack at these temps with the damper open. We'll see later on when I close it. This is a much different operational unit than the CAT version. I suspect if this works, that will be OK, but people need to know these things. Draft is a little better today, and it is a little colder, so we should have a real "sucker" when it finally cools off. As a note, I've had the Defiant NC drafting for primary air wash apart and it is a direct feed from the large hole in the stove bottom. The draft control is a direct linkage that operates a flapper above the doors for primary air/wash. This same large hole is a direct feed into the shoe refractory (where the secondary air input siphon holes are) with the only restriction being the area of the opening of the holes in the shoe refractory. Increase area of openings, more air, decrease openings, less air. So, when the front/bottom holes are blocked by ash there is a restriction on air inflow for secondary combustion. (unless the air is mystically getting through the ash). The Defiant NC parts diagram is all you get with this stove. It is on the VC web site. No airflow diagram: but above is how it works. The stove is very tight. So, I just closed the damper with the stove at 600 stove top/550 pipe. I everburn fired off for about 45 seconds and stalled, when I went outside, lots of smoke out the stack. I'm going to try again. Well, no "rumble" but it sure is HOT. 350 pipe/550 stove top. I'm going to bed and I'll see how it looks in the morning. On the CAT version the morning stove would have coals and lots of white on the griddle top where all creosote residue had burned off. Let's see what happens with this. Something tells me we are going to go up a pinch on the diamerter of the siphon holes. Perhaps that's what she needs. I will wait for colder weather to verify. VC should pay us for all this thinking... You all are great and I enjoy the forum a lot. I have about 15 stoves, I love the old ones. They use a bunch of wood, but the burn w/o creosote and keep things warm. My favorites are an old Army Cannon Heater, an Old Oak stove with lots of nickel and a coal stove I have that stands about 5'6" tall with a large ring around it so you can sit around it and put your feet up. (not for long HOT) And lastly, there is an old light green and yellow porcelain princess kitchen stove. (We had one of those on the farm in NH where I lived as a boy) Good night to all!