Woodstock Wet Wood Burn Video

[Todd]

http://www.youtube.com/watch?v=CmReSRqaquE&feature=digest_tue

Just saw this on youtube. Looks like the owner Tom playing around with his new toy.

 

[brogsie]

And the results?

 

[Lumber-Jack]

And the results?

(broken link removed to http://www.woodstove.com/images/editorial_support/PDFs/wetcordwoodtesting1.pdf)

 

[begreen]

Fun test and some interesting results. But the PH is a hybrid that doesn't run on cat only, correct? If so, isn't that stove going to burn with a combination of the catalyst and secondary air?

 

[brogsie]

Thank you Todd and CL.
The cat will even cean up a wet wood burn.

 

[Todd]

The way he had that turned down so quickly looks like it was all cat burn til later on after the wood dried out. If you did this with a non cat stove it would of been a smoke dragon and never lit off. On the other hand you can't continue to burn this way in a cat stove because eventually it will clog up the screen and cat and have the same dirty burn as a non cat.

 

[Lumber-Jack]

Seems like a pretty good stove actually. I like how after 3 hours of smoldering wet wood the heat from the cat was able to ignite the secondaries. There is no way secondaries in my stove would spontaneously start up after smoldering that long.

[youtube]http://youtu.be/CmReSRqaquE?t=5m29s[/youtube]

 

[HollowHill]

Thanks for posting this, Todd. It was interesting to watch. Now THAT'S a moisture meter. I drooleth...

 

[BillsWS]

Was that a little smoke on the glass or just reflection? How is the glass staying you guys that already have their PH?

 

[DexterDay]

Loaded full of wet wood.... Shut down completely And still an amazing burn rate!

Wow... I want one. I know you cant run it like that all the time (clogged cat) but its still impressive .. ;-P

 

[Backwoods Savage]

Another thing I noticed is that Tom loaded the wood bark down. I've always had much better burns with the bark up. It might be an interesting experiment for someone.

 

[NH_Wood]

If I'm understanding the video correctly, the stovetop temp leveled off (after dropping) to 300* and then stayed at that temp. Seems to indicate that wet wood still ain't too good in this stove, but I guess that wasn't the point of the video! Cheers!

 

[Backwoods Savage]

No, I'm not convinced that burning wet wood at any time is good. It is too bad they didn't have some of our wood to use in the experiment. :cheese:

 

[corey21]

That was interesting.

 

[Waulie]

Cool!

The second load looks just like my typical low burn (I'm not burning 30+ percent moisture wood like they did in the first run). I'll usually put maybe 50% more wood than that in with similiar results. Stove burns with flame for a bit, goes dark for a while, then gets occaisional secondary bursts. This usually takes the stove up to about 450 and I usually reload after 8 to 10 hours with the stove around 250. I can't believe how little wood I've burned since I got the stove and my house is nicely toasty!

I can't load it full without the secondaries taking over and getting tons of heat, but since 8 to 10 hours works great for me, I'm very happy! When temps plummet, I fill it up and the stove throws massive amounts of heat to keep me warm.

 

[Battenkiller]

If I'm understanding the video correctly, the stovetop temp leveled off (after dropping) to 300* and then stayed at that temp. Seems to indicate that wet wood still ain't too good in this stove, but I guess that wasn't the point of the video! Cheers!

Temp with the dry wood was only 338º on the average at that low burn rate, so there was a difference but not a huge one.

I don't get the MC claims, however. I'm gonna go ahead and call "foul" on this one. Resistance-type meters give results using the dry-basis calculation, not wet-basis, or at least all the ones I'm familiar with. A meter reading of 36.4% MC would equate to a wet-basis water content of 26.7%, not 57.2% as they claim.

Still, a mighty impressive stove to burn damp rock maple at low temps like that.

 

[Huntindog1]

In the video something to take note of:

This stove was using some kind Cat combustor developed for diesel engines.

Plus the results page says this:

Please note: we are using catalytic technology not available during the last NSPS.  We are 
using catalysts made of stainless steel “durafoilâ€.   The thickness of the material is about 
0.0025â€Â (2.5/1000), and where it is bonded the maximum thickness is about 0.0075â€.  The 
thin walls and high cell density result in a huge surface area to face area ratio (meaning 
more catalytic activity); quicker responsiveness at low temperatures; and less resistance to 
flow.  This has been one of the best innovations in the hearth industry over the last decade, 
but you wouldn’t know it by talking to HPBA

Is this special cat available in all wood stoves today?

 

[Todd]

In the video something to take note of:

This stove was using some kind Cat combustor developed for diesel engines.

Plus the results page says this:

Please note: we are using catalytic technology not available during the last NSPS.  We are 
using catalysts made of stainless steel “durafoilâ€.   The thickness of the material is about 
0.0025â€Â (2.5/1000), and where it is bonded the maximum thickness is about 0.0075â€.  The 
thin walls and high cell density result in a huge surface area to face area ratio (meaning 
more catalytic activity); quicker responsiveness at low temperatures; and less resistance to 
flow.  This has been one of the best innovations in the hearth industry over the last decade, 
but you wouldn’t know it by talking to HPBA

Is this special cat available in all wood stoves today?

There have been steel cats before and they didn't work any better than the ceramics, maybe these are better, I don't know for sure but trying to find out more info from the manufacture.

 

[Todd]

Looking at the result chart those emission gph numbers really stick out to me. Low burn rates under 1gph is pretty darn clean.

 

[Buck1200]

I'm pretty certain the cat he (Tom M.) is referring to in his report is the new standard stainless cat WS now sells in all of their stoves. The unit in the video looks exactly like the one which is in my Progress. NSPS is "New Source Performance Standards" for wood burning equipment emissions limits. I believe Tom is suggesting that if this cat had been available during the last round of review, then there would not be any discussion of reducing smoke cleanliness standards, as apparently some manufacturers were lobbying for.

 

[jdonna]

Interesting experiment. I hope woodstock continues to release the videos.

I also found it interesting that they were very quick to close the bypass damper on it. I have on accident loaded my fireview with the damper closed and found really good burn results on a reload.

 

[Stump_Branch]

I noticed he opened the lid in the beginning, always thought this was a no no. But i guess its when the cats running. I tried it last night when i got home. Luke warm stove and coals, threw some wood on and took a peak. No spillage of smoke at all. Neat to watch the draft from that perspective. Dont to it with a hot cat though.

I get the claim of more cells in the stainless cat, but i believe ceramic has more surface nooks and crannies in those cells, making more surface area. I want a spare cat on hand, be nice to try a ceramic. Just dont want to part with the hundred or so bucks to expirement...

Interesting video though. Certainly tested the thermal shock of the steel cat pitching in wet wood like that.

 

[Huntindog1]

Ok on the stainless vs ceramic , I remember now that cats were made of ceramic as I owned one as an add on back in the late 1980's from Nutec Corp.

I see now why the Wood Stocks can burn wet wood as with it being stainless steel you dont have the issue of cracking the cat if its made out of stainless steel vs ceramic.

Plus sounds like with its better sensitivity it isnt effected by the moisture cooling the combustor out of its operational temperature range.


"result in a huge surface area to face area ratio (meaning more catalytic activity); quicker responsiveness at low temperatures; and less resistance to flow. "

I wonder what the lowest activation temp is on this new combustor as he was operating that wet wood test at pretty good smoldering.

But as I sit here and think about it he first had the stove heating up before he put the wet wood in. The combustor was already pretty hot. So once the wet wood got in the stove the combustor was most likely hot enough to work immediately thus be self maintaining the heat as it was immediately burning the gases creating its own heat to keeping its temp up so as not to fall out of the operational range.

The Ceramic combustors you wasnt supposed to use wet wood as water hitting a 1200 degree ceramic would cause it too crack up.

I am not sure what the specs are today on ceramic combustors but in the early days they had to be operated at a higher temp to keep them going thus it would be much easier for moisture in the wood to cool them out of operating. Maybe this new cat has such a low temp spec that its hard to cool it out of its operational temp range.

 

[Todd]

They claim the steel cats light off at a lower 400 degree temp vs 500 for ceramic and according to my cat probe it does light off that low but I wouldn't recommend lighting off so soon or just engaging right after throwing the wood in there. Cat stoves run with such low flue temps that it's a good idea to let her rip in the bypass mode for a good 10-20 minutes to warm up that chimney and maintain a good draft. I found this out the hard way.

 

[Battenkiller]

Cat stoves run with such low flue temps that it's a good idea to let her rip in the bypass mode for a good 10-20 minutes to warm up that chimney and maintain a good draft. I found this out the hard way.

Yeah, let's not lose sight of the fact that the Woodstock R&D dept. uses an induced draft chimney. Makes lots of things easier for them, while we mortals are stuck with a draft that varies considerably according to flue temperature.