Progress ( woodstock)

[Battenkiller]

So, if it is just down to a smolder, does that mean the burn tubes are not active and only come into play once the stove reaches a certain temperature?

Interesting question. I'm not sure, but my guess is it probably has to work that way. Cat only at the low output end, a mix of both in the mid-range, and almost entirely primary and secondary combustion at high-output makes the most sense to me.

 

[Flatbedford]

So, if it is just down to a smolder, does that mean the burn tubes are not active and only come into play once the stove reaches a certain temperature?

I think that is what they set out to do when they designed it. Woodstock has the long smolder thing figured out already, I think they added the burn tubes to increase high output.

 

[BrotherBart]

And we'll laugh at the observations and conclusions of a team of experts in white lab coats who have every high-tech data gathering gadget and gizmo needed for both qualitative and quantitative anaylysis at their disposal, but we'll blindly trust the words of a grumpy old curmudgeon in bathrobe and slippers, dozing in his recliner with a Natty Light in his hand, who gets all his information about what is going up his stack by watching the window of his stove because he thinks watching football is a waste of his time. :lol:

Not true. No recliner. :smirk:

 

[pen]

So, if it is just down to a smolder, does that mean the burn tubes are not active and only come into play once the stove reaches a certain temperature?

I think that is what they set out to do when they designed it. Woodstock has the long smolder thing figured out already, I think they added the burn tubes to increase high output.

Yep, the secondary air is not unregulated like it is on many stoves. When the primary is closed all the way down, the secondary is closed down quite far also. If you leave the air open a bit the cat isn't going to have much work to do but your burn time will be shorter and greater heat output also.

pen

 

[BrowningBAR]

So, if it is just down to a smolder, does that mean the burn tubes are not active and only come into play once the stove reaches a certain temperature?

Interesting question. I'm not sure, but my guess is it probably has to work that way. Cat only at the low output end, a mix of both in the mid-range, and almost entirely primary and secondary combustion at high-output makes the most sense to me.

That's what I was beginning to understand as well. At what point is a stove defined as 'low output'? Sub-300°F? At what temperature does the secondaries come in to play? 500°? Because at sub 500° on the Heritage the secondary show really slows down.

My point in this is that, if I buy a Defiant or a Woodstock HP, the vast majority of the time it will probably be running at 400° and under. Rarely would I need it at over 500° due to the fact that I am over-sizing the stove to such a large degree. Would I not be seeing the benefit of the 'hybrid'? In theory would I be better off going with the cheaper Defiant (or Buck) as the high output would rarely be reached?

 

[pen]

I have lots of faith in science, not so much in moisture meters. I watched 3 different ones probe the heck out of the same pieces of wood and the one was reading the in the single digits, the others in the mid teens, the other in the mid 20's. Which one do I trust? (The one btw was a very fancy SS job w/ a built in slide hammer for driving the pins in). The other two were personal lower dollar units.

At the end of the day I really don't give a flying poo what the actual moisture is, all I know is when loaded in the stove Dennis's wood took off a ton quicker than the wood that the woodstock guys had around which if you asked had been sitting in doors at the factory since this time last winter. In fact, guess what wood they (the woodstock employees) used when people were starting to really show up and want to see that puppy in action w/out fuss.

Proof is in the puddin'.

pen

 

[oldspark]

I have lots of faith in science, not so much in moisture meters. I watched 3 different ones probe the heck out of the same pieces of wood and the one was reading the in the single digits, the others in the mid teens, the other in the mid 20's. Which one do I trust? (The one btw was a very fancy SS job w/ a built in slide hammer for driving the pins in). The other two were personal lower dollar units.

At the end of the day I really don't give a flying poo what the actual moisture is, all I know is when loaded in the stove Dennis's wood took off a ton quicker than the wood that the woodstock guys had around which if you asked had been sitting in doors at the factory since this time last winter. In fact, guess what wood they (the woodstock employees) used when people were starting to really show up and want to see that puppy in action w/out fuss.

Proof is in the puddin'.

pen

Well my MM has been in tune with my "real world" findings so that is why I trust mine, not sure why so many people are skeptical of certain things.

 

[pen]

Well my MM has been in tune with my "real world" findings so that is why I trust mine, not sure why so many people are skeptical of certain things.

I'm skeptical because I just watched 3 give very different readings!

pen

 

[Battenkiller]

I have lots of faith in science, not so much in moisture meters. I watched 3 different ones probe the heck out of the same pieces of wood and the one was reading the in the single digits, the others in the mid teens, the other in the mid 20's. Which one do I trust? (The one btw was a very fancy SS job w/ a built in slide hammer for driving the pins in). The other two were personal lower dollar units.

At the end of the day I really don't give a flying poo what the actual moisture is, all I know is when loaded in the stove Dennis's wood took off a ton quicker than the wood that the woodstock guys had around which if you asked had been sitting in doors at the factory since this time last winter. In fact, guess what wood they (the woodstock employees) used when people were starting to really show up and want to see that puppy in action w/out fuss.

Proof is in the puddin'.

pen

Well my MM has been in tune with my "real world" findings so that is why I trust mine, not sure why so many people are skeptical of certain things.

OS, I think we have the same one, don't we? The blue HF $12 jobbie? All I know is that I compared mine to wood that I later did an oven-dry MC test on several occasions and it was always within a few percentage points of the true MC. Even a $500 meter won't be any more accurate than that at firewood moisture levels.

I don't think the "proof is in the puddin" is something to stake your life on....

I have said this many times, so don't throw a brick at me for saying it once more. The photo in my avatar was taken about one second after I flung open the doors of my Vig. Inside there is about 20 pounds of black birch that just doesn't get much wetter - about 57.5% MC as very carefully determined by using the oven-dry method (sorry, no meter in the world will give accurate results on a MC that high). You are seeing exactly what I saw: no smoke at all in the box, no smoke from the flue, and no smoke from the flue when I shut the bypass and sent her into secondary combustion 20 minutes or so later. Stove at 700ºF, flue temp stable at about 450º once in secondary (downdraft) mode.

How is this possible? I know, I know... you'd never be able to do that in an EPA stove. Well, I might say that the old VCs were capable of achieving secondary combustion, and I do it all the time with my stove, but I'll let that argument alone for now. However, I've also heard it said over and over that you can't do that in any stove, that the green stuff will just sit there and smolder and fill the flue with massive amounts of creosote, that this is why the EPA stoves were developed in the first place... yada, yada, yada.

BTW there was nothing even vaguely "scientific" about this photo. Just some very green wood, a scale, a match, a stove, and a camera. Strictly observations. No hypotheses, no doctoring of temps or other data, no Photoshopping (hell, I still have that annoying looking "face" showing in the flames). The proof is in the puddin' here as well AFAIC, ain't it? But no one will ever believe it because it seems to violate every concept they have ever heard about burning wood. It doesn't, however, violate anything the woodburning technologists are saying.

Me, I'll continue to trust meters, and sensors, and scientists, and engineers, and wood technology, and good common sense at the end of the day... and leave everybody else's anecdotal proof to them. I have a hard enough time understanding the reasons behind my own observations.

 

[oldspark]

Well my MM has been in tune with my "real world" findings so that is why I trust mine, not sure why so many people are skeptical of certain things.

I'm skeptical because I just watched 3 give very different readings!

pen

That does surprise me, mine has given me constant readings unless the battery gets low.

 

[oldspark]

BK-yes I have the same one as you and I will swear by it not at it. :lol:

 

[Battenkiller]

I'm skeptical because I just watched 3 give very different readings!

Pen, I didn't see the fancy slide hammer version in use so I can't comment on it. It is possible to use these things incorrectly, or to have bad batteries, etc. What I can say is that Tony and I both got the same MM readings on the same splits. 25-27% MC on the inside of the ash split, 17% on the outside. 16% on both the inside and the outside of the cherry split. I showed all of this to Dennis as he stood right there. As I said, there was no doubt there was still excess moisture inside the ash split. It was slightly damp and cool to the cheek and even still had a faint smell to it. I've been handling firewood for over 25 years, I have an IQ that is at least a couple points higher than my firewood, and I can tell the difference. Can I explain why it was that damp? Not in a million years. Should be around 16-18% MC according to any wood industry resource in the world.

Now, would I burn this wood in my stove, wood that tested at 25% MC on an electrical resistance moisture meter? Any day of the season, in any stove anywhere on the planet! Why? Well, as excerpted from the text of Method 28:

7.1.2 Fuel Moisture. The test fuel shall have a moisture content range between 16 to 20 percent on a wet basis (19 to 25 percent dry basis). Addition of moisture to previously dried wood is not allowed. It is recommended that the test fuel be stored in a temperature and humidity-controlled room.

As I was explaining to you at the Woodstock plant about the "fuzzy math" that is used to calculate MC in moisture meters, 25% MC on a meter is a dry-basis calculation that is fully equivalent to 20% water by weight regardless of how anybody feels about the logic of using this method of calculating MC - it simply is the way it is. I didn't make the rules that govern how MMs are calibrated, only reporting with certainty how it is done. But this reading on a meter is also, coincidentally, right at the upper end of the MC allowed in the EPA test load. And I can't comment about the science used to make that call, just reporting how it is.

Notice... No fair adding water to your wood to get it to burn cleaner during the EPA test procedure, it has to be air-dried down to that level and kept in a humidity-controlled room to keep it there. Relative humidity in that room, BTW, would have to be between 87% and 97% for the wood to stay within that range according to this chart that is universally used throughout the world to determine the EMC in the long-term storage of wood.

 

[RAPhomme]

Can this stove be turned way down to a smouldering long cat burn without the secondaries kicking in?

Yes, without a doubt. I sat in front of it and stared into a flameless box without a hint of smoke anywhere inside coming from the two fresh splits that were placed inside on a big, hot coal bed. A little more air and the Borealis came right back to life. Stove output range during the EPA test was about 10,500 BTU up to 75,000 BTU. That's a very impressive range to me, and I'm sure it could be tweaked at either end of that range when at home by using cordwood and experience with your individual setup.

Thanks BK for the observations and close attention. Love the science, love the curiosity.

Does appear to me that there's actually quite a bit of sort-of-hard data on the stove, back there in the shadows, which could be parceled out a bit more generously/quickly, without fear of misleading our expectations.

For example, yours is the first mention of the actual EPA range I've seen--no big deal, but why not just get it out there? It's a good thing, right? Same with the concept of controllable secondary air--it's hinted at in the blog, but never stated directly. What a nice feature--why not explain it?

Still think Woodstock would be well served by giving a narrative/analytical tour of their beautiful new stove. As in: here's this cool feature, here's why we did it, here's what it does, here's the general range of performance it generates. Of course, of course, it's too early in the production stage to do so--but they do keep saying that the real stove is performing "exactly" as the prototypes they've been developing for years. Someone obviously has a pretty good idea by now.

Over-hasty conclusions to draw so far:

1. stove is a big heater for its size.
2. efficiencies are very good without being record-breaking.
3. real-world btu outputs over times are still a mystery/being worked out/unspecified.


Two last questions:

1. did anyone find out what the current general sense of the real-world low-burn time is? When they say "up to 16 hours" on the website, is that really the more-or-less max at the lowest functional setting? Or is that "conservative," etc.?

2. did anyone ask about the thermostat option? I know lots of folks were interested in that.

 

[SmokingAndPoking]

75,000 BTU/hr on the EPA test cycle Category 4 burn? Are you certain? That makes the Cat 4 burn rate about 6.27 kg/hr (13.68 lb/hr). Wow that's fast. That means the test only lasted for about 1.5 hours at the longest. Its amazing that were able to keep the fire clean burning at that high of a DBR.

 

[pen]

My meter reads 35% MC when tested there, which is what it's supposed to be, except I figure mine's about 15% MC because it's been seasoning for 59 1/2 years now. I need a new oven, too. Damn meter agrees with the oven-dry method, so now that I know my meter if off, my oven must be off as well. My oven-dry wood must be 20 points lower as well... about minus 20% MC. %-P

No doubt Dennis's wood burns well after being well seasoned. This is the reason that I never get concerned about moisture values.

However, if we agree that your measurement is right and that split is at 25%, lots of folks have problems with 25% wood when it hasn't had good time to "season." Once they get well seasoned wood they don't seem to have trouble.

I wonder if it's like a dry-aged steak. Part of the reason the flavor of the steak is so good is because the moisture content is low, but the other part is that enzymatic action has partially changed the steak itself. Throwing a steak in a food dehydrator is not going to give you a dry-aged steak.

I wonder if part of the reason that "seasoned" wood burns well is not simply because of a reduced moisture level but if something else is changing inside of the wood which helps promote its burning potential?

pen

 

[oldspark]

Not sure I follow your logic Pen.

 

[pen]

Not sure I follow your logic Pen.

Take 2 pieces of ash, both at 25% moisture. One split and stacked for 2 years, the other for 2 months. Will they burn exactly the same? Or does the time that wood had "seasoning" allowed enzymes found in the cells of the woods to begin changing the wood structure so that it burns better?

In other words, are there other factors beside straight moisture content affecting the characteristics of the wood which could make a difference in how well they burn?

Basically, if that wood really is 25% moisture, I'm trying to figure out why it burns so darn well?

pen

 

[Slow1]

Two last questions:

1. did anyone find out what the current general sense of the real-world low-burn time is? When they say "up to 16 hours" on the website, is that really the more-or-less max at the lowest functional setting? Or is that "conservative," etc.?

2. did anyone ask about the thermostat option? I know lots of folks were interested in that.

1. The 16 hours is "Based on the extensive lab testing" and is subject to all the general vague definitions. However, the person I spoke to on the subject (sorry, I forget who it was at the time) was confident that it was a meaningful number - i.e. stove would still be warm (more than 200* on the sides) and easy to re-start from the coals inside. Certainly not flaming and increasing the temperature of your room for 16hrs wit active secondaries

2. THe thermostat option apparantly has been turned over to a sub-team who is working on it and they are 'making good progress.' However nothing is ready to be announced there. It seems they are going 'big' on this - aiming for not just a passive thermostat but a solution that will do a bit more and really improve the entire burn cycle. Thin on details - I had learned a bit about this subject last year as well and can only infer the direction they may be going here. I'm not sure I am entirely supportive of a more complex solution, but will have to wait and see what it is (whenever it comes out) before judging but don't expect anything too soon. I think for the initial release we can expect a nice knob to set the air level and that is about it.

 

[ddddddden]

Good answers, Slow1. Norum, Woodstock is generally conservative with their numbers. For example, their 10-12 hour figure for burn time in the Fireview is easily achievable. More like 8 hours on the c-c-cold days, when you need to push it, and easily holding coals for 20 hours on mild days when you don't need to reload. Basically, the Fireview needs reloading 2x/day, 3x on colder days, so I think their "10-12 hours" is on the money. I'd imagine that "16 hours" for the New Stove is going to translate into reloading 2x/day on most days, and holding coals for longer if you want to let it coast. Pen, that is a very interesting question about the structure of the wood changing. . .

 

[Todd]

I agree, Woodstock's stated burn times are pretty close. My Fireview easily went 12 hours on a full load of Oak or Locust with enough coals for a new load. The Keystone can also go 12 hours but you have to make sure you pack the box full, 8-10 is easy peasy.

The thermostat option sounds interesting, I hope they can incorporate it into their other stoves as well?

 

[ddddddden]

+1 on the thermostat. Way to step up and take on BK and the Aliens! :cheese:

 

[3fordasho]

FYI Woodstock has recently determined that it is potassium poisoning of the catalyst rather than excess water that causes premature cat failure. The potassium is in the fly ash, so the screen catches it before it hits the precious metals. The secondaries will also help you get up to seven years out of a $150 combustor because they will burn most of the smoke off during a high-output burn before it hits the cat. Unless it's set low to smolder the wood, the secondaries get most of the smoke, while the cat just catches whatever gets by the secondaries.

Over the summer I replaced the 2nd ceramic cat in my fireview with the new SS unit. I asked if the new cat scoop and screen offered any benefit over the un-warped older design unit... Woodstock rep on the phone said no. If the new screen is going to protect the cat I'll be more than happy to spend a few bucks on it..

 

[Flatbedford]

I bought the new scoop kit for the Fireview when I was there. This season I will be burning with it and the SS cat. I'll report any changes. I will also be burning better fuel this season so I won't know if it is the improved scoop and cat or the well seasoned White Oak and Black Locust instead of the Cherry/Maple/Ash mix I burned last year. I changed to the SS cat mid season last year and I did see a significant improvement in heat and burn time. I also got to the Ash section of the wood pile about the same time. I guess my observations are not high quality scientific method.

 

[ddddddden]

I dunno, Tim. Maybe they thought you meant performance increase benefits. The openings in the screen are a lot smaller, and it wraps around to cover the L/R sides of the scoop, which the old unit does not do, so it's hard to see how it wouldn't be more effective in keeping ash off the cat.

 

[Battenkiller]

Basically, if that wood really is 25% moisture, I'm trying to figure out why it burns so darn well?

Because 25% MC dry-basis is the moisture content the stoves are designed to burn, and the moisture content that the EPA test procedure specifically demands, and the moisture content that those idiots in white lab coats have been saying for over 30 years burns most efficiently in an air-limited wood stove. Or to say it another way, a 25% MC reading on a moisture meter IS the Holy Grail of 20% MC by weight.

Again:

7.1.2 Fuel Moisture. The test fuel shall have a moisture content range between 16 to 20 percent on a wet basis (19 to 25 percent dry basis).

The stove manufacturers themselves specify how their stove should be burned during the test. Heck, if I buy a stove that can't handle the MC of an EPA test load without problem, just what is the point of designing for the test in the first place? You saw the numbers from the EPA test on the Progress Hybrid. That test was done with doug fir that was air-dried to between 19% and 25% MC. The test load could be anywhere in that range and the stove is supposed to basically work the same. What is there to doubt?