Production Woodstock IS

yeah he has an OAK, installed.. I got great draft up 2 ft 90 18 inches to thru wall 27 ish feet straight up.. measured at 60? pascals.. too much draft is not problem burning now 42 and rain.. wondering if it is an OAK problem.. cat is hyper first few times.. follow 2 by 4 idea and post results.. thinking it's a little bit of inexperience and maybe an air issue... I had similar problems first few weeks... then it came together... warped baffle?

 

Here are the last 2 nights fire data graphs, with and without modified radiator.

Both nights I tried to have a similar loading (half load). Outside low temps were within 5 degrees, 35 and 40 respectively. The Catalyst was engaged at 600*. The draft was set at the 6-7 line. During colder weather, I usually close the draft to the 3-4 line and run with a "black box", I believe in those conditions the temp difference may be a little greater.

 

Quite a difference with the mod in the early stages of the burn.

 

Yes, it's connected to an OAK, so that should resolve the "house too tight" problem for the primary and secondary air but it still behaves like it has that problem.

I'm thinking of buying some ecobricks from TSC to test the wood theory but it's hard to imagine how it could be the wood when the moisture meter claims all the wood is more than dry enough.

Either way, it's not going to be cold enough to make another test for at least a week which means I'll be stewing about it for all that time.

 

Yes, and I find that interesting because it is in the middle- to- end of the burn where I find the radiator blocking plate really makes a difference. Well, I guess at the beginning too because I can run the stove a fair amount lower so the initial burn is lower too. But the big change that I was looking for and found was a much longer cat. burn before all the volatiles are burned off and it becomes a pure charcoal burn.

Erick, you might want to try a damper, installed low in the pipe (close to the stove): it made yet another change in the behavior of the stove for me much like blocking the radiator did- closing the damper all the way and then opening the draft one or two lines makes the initial burn slower but significantly extends the time the stove top stays hot (at or above 300 F for me).

Brian

 

Did you post graphs of this damper usage? While I don't own an IS, I do have a pipe damper (28 ft chimney) and have been trying to figure out how best to use it.

 

What you were referring to as the baffle is probably the secondary manifold. It is normal for this bend in and out. Notice the bolt in the middle. That is there to keep the manifold from bending too much.

 

At some point I may try the damper but,
I have double wall flue pipe and with the current set up I burn a little over 2 cords/yr to heat 1900ish sqft. That is with a full load once every 24 hrs of strategically stacked wood every time, which made the house too warm (78°). This season I have to find the right load as to keep the house at an ideal 70-73°. That should cut back on the amount wood I use.

 

BDF what did you call the process when the steel get up to temperature and flakes? tried looking it up but all I got was welding info... I appreciate your knowledge.. want to make sure I am correct when I try to explain thing to my wife..

 

It is called scaling or flaking but I use the term scaling because that is what they call it in steel mills. If you ever happen to see steel being made / processed, you will notice when steel is extremely hot, such as when it is being rolled (HRT or Hot rolled steel), there is a black crust that forms on the surface of the metal. This is the scale and when it falls of, that stuff is the flake(s).

Just to expand a bit on this because it seems most people are unfamiliar with what is happening: everyone knows carbon steels, virtually all types, corrode or 'rust'. Raw steel left in the environment will rust, eventually pit and the flakes will fall off. What is happening is that the iron is chemically reacting with the oxygen in the air and forming oxides of iron (there are three, ferric oxide, ferrous oxide and magnetite, the most common one being ferric oxide, dark red in color and commonly seen as typical "rust"). Which, by the way, is the identical chemical process (oxidization) that burns wood! Anyway, what is not nearly as well known is that oxidation rates change with temperature: raise the temp. and the oxidation rate increases. Increase the temp. a LOT, and the oxidation of steel happens fairly quickly- fast enough so that it can be seen in 'real time'. So what is happening to our radiators is that they are simply rusting but doing so relatively very quickly due to the high heat; steel starts to scale pretty fast when it starts to glow, or about 900 degrees F. As our combustors typically run between 1,000 F and 1,400 F, and the radiators are directly above and quite close to the cats, they get close to the same temperature and scale quickly. There is no way around this by the way, it is just chemical reality. Stainless Steel resists corrosion much, much better than carbon steels and that difference shows very fast at high temperatures, which is why Woodstock is now putting a stainless steel sleeve over part of the radiator- it will corrode but not nearly as fast and not fast enough to make true scaling.

Just as an aside, if you get steel hot enough to turn bright red / orange, around 1,400- 1,700 F, and add pure oxygen, it will actually 'burn', just as any flammable material does. This is exactly what happens when using an oxygen based cutting torch; the torch flame heats the steel to the point where it will react very rapidly, almost instantly with oxygen, and then a stream of pure oxygen is injected directly against the hot steel with the result being that a narrow path of steel is immediately fully oxidized and pushed out of the way. The material left, called slag, is really just an oxide of iron although not ferric oxide so it is not red but medium gray in color. Another fascinating part of this is that when actually gas- cutting steel, the majority of the heat is NOT produced by the burning fuel gas(s) but by the actual oxidation of the steel itself; the 'cutting' action provides the heat needed to continue to cut the steel, which is why steel gas- cuts very quickly but starting the process is really pretty slow.

Betcha' that is WAY more than you wanted to know, right? Next week's class will be about physics, sub- titled "Is there really any such thing as gravity or does the Earth just suck?".

Double

Brian

 

Outstanding because I am burning more like 4 cord to heat about 1,400 sq. ft. and doing it as efficiently as I possibly can. Perhaps there is something to all this talk of the mystical 'insulation' I have heard mention of? My house was built in 1905 (and as a barn, not a house until 1948) and there is none of that new- fangled stuff in the walls. When the new second floor goes on it will get the [current normal] 6" of insulation in the walls and 15" in the attic but there still will not be any in the first floor walls. I am toying with the idea of drilling holes in the outer sheathing and filling the wall cavities before the whole house gets re- sided.

Anyway, my very limited experience was that a damper helped when going to a better (taller and insulated rather than short and masonry) chimney. It helped to even out the burn, slowing it a bit at the beginning and leveling out the middle- to- end of the burn. The other thing that helps quite a bit is to close down the secondaries- I find they are a bit too big when the stove is full as the secondaries burn the top 1/2 of the fuel load pretty aggressively.

Brian

 

15 minutes into a reload in 49 degree weather. It's windy though. Air at 50 percent and cat engaged 5 minutes ago. It's climbing. It's at 800. Hard to see in the picture but small secondaries in the back left corner. I'm sure when I add the 2 to 3 foot of chimney it will perform even better. That's why I'm stumped on the posters sluggish stove with 17 feet of chimney to my 12.5 feet.

 

That's easy to see, yours is breathing fire. I see your pets hiding behind the glass.

 

Erick, what plans do you have to change the way you burn to keep a lower household temp?

 

Where do you get your stove temperature readings from?

 

Catalytic Wood Stoves Shown to Increase Dioxin Emissions

Has anybody read this? I would love to get Woodstock's view on this.

 

It won't take long to get the burning habits of this stove down, in a way that it works for you. You'll get a feel for your draft, how to reload on a bed of coals that will get your temps back up quickly and closing it down and cruising until the next reload.
To be honest, I think your in the best spot to be able to get the info you need to get this down. Most of us here are owners from the first or second year and depended on each others posts to understand the stove better.

 

Does that article just consider stainless steel cats with precious metals attached to it's grid vs. a ceramic cat? I'm not so friendly with catalyst makeups, do ceramic cats use precious metals too? I was looking at Condars website and they use Palladium/Platinum on their metal cats.

 

I am now 100% sure that the stove has a breathing problem and I'm ~90% sure it's the stove's fault.

I went down to TSC and bought some of the Redstone compressed sawdust bricks, which have ENVIR cast into them and I'm running an experimental burn with them right now and it's not going well, basically exactly replicating my results with cordwood.

1) I experimented with the OAK attached and with it disconnected, with the doors to the house open and with them closed. The results are the same in all cases. So it clearly has nothing to do with the supply of air to the stove intake

2) I've used cordwood that measures 12-18% MC and I've used bricks and both produce exactly the same results. It's clearly not a fuel problem either.

3) The stove will suck air like mad if the ash pan door is open, give it a few minutes and it'll start to rumble and vibrate and burn like crazy. I can control the rate of burn by closing the ash pan door partially. When the ash pan door is just touching the seal but still leaking freely, the stove burns in a controlled and stable manner. This implies to me that the chimney system is capable of providing enough draft to supply the fire if it has access to air.

4) If I close the ash pan door and rely on the fully-open in-stove air source, the fire falls on its face or even goes out. I had it racing at the rumbling and shaking stage, gently closed the ash pan door over the space of about 20 seconds, and the fire was out about 30 seconds later. Not down to embers, OUT. No glow or light of any kind and it did NOT spring back to life when I gave it full ash pan air again. I actually had to open the door and re-light the fire.

5) With the ash pan door partially open, flue temps rise and the fire builds as you'd expect. However, I managed to close the ash pan door and keep the fire lit-ish and the result is flue temps that are still falling. They're currently at 250F and dropping about 2F per minute as the fire continues to dwindle.



With all this, can you guys see any possible explanation other than something between the air intake on the stove and the firebox is not functioning properly and is cutting off, or nearly off, the supply of air?

 

The 800 was my cat temp. I also have a probe thermometer in the double wall pipe and a magnetic thermometer on the stove top about 3 inches to the right of the chimney collar. I generally only look at my cat probe but I do glance at the one in the stack on occasion but that's generally only on start up.