A better explanation...

[greendohn]

My 1st experience with "EPA" tech. was on my cousins LOPI, aprox. 6ft. of single back pipe goin' into an old exterior masonry chimney maybe 15ft tall. Works like a charm! 1st time I witnessed the 2ndary burn tubes "gassing" I stood with me pie hole agape in amazement, that stove is still burnin' wood and burning it completely. A single draft control, I don't know what all it controls or shuts down when employed,,it must have "air wash" 'cause the glass/ceramic stays pretty clean.
Fast forward to last year. My best pal built a brand new stick built home, spray in insulation, single story,,air tight. I sang the praises of "EPA" 2ndary burn tubes, I also mentioned "CAT" stoves and admitted I'd not seen "CAT" stoves in action.
He picked up a new stove, air wash front door with the 2ndary burn tubes. A couple sticks of black pipe straight up into SS(with attic shield,stove installed to IN. code),,,3 sticks,,9ft of SS chimney thru the attic with a stick or two of SS to the rain cap. WELL seasoned hardwoods and his stove MAKES CHARCOAL!! LOTS OF IT!! I'm currently trying to convince him to use the outside air intake to see if any improvement is found. Thoughts,,ideas? His first thought was a GRATE to get air UNDER the fire!! I told him to save himself the trouble and 4-get the grate!! LOL,,
Looking into the 2ndary air is something I will tell him about, see if a mod to slow that down and create more primary air and improve his burning of coals..He currently gets 6 hour burn times at best with well seasoned hedge.
I find this to be a good thread and sure do hope yer new stove will be what yer looking for Spidey.

 

[Steve NW WI]

CSA B415 is a standard (what or where the test results must be), the EPA "standard" is available on their website and I do believe it is the same(?) as the CSA standard.
But if you want to read the step-by-step "how to preform the test" a certified lab must use, you have to submit a request in writing, stating the reason you need a copy, and send them a check (go figure).
If your stove control allows you to completely close off the air intake there is has to be a hidden, fixed and unregulated opening somewhere... to pass certification the stove must be tested at the lowest possible user setting. Anything else would render the reason for EPA certification a moot point... remember, the reason is to stop the stove (and user) from polluting like the old air-tights could be made to do (i.e. choking them down too much).

Here's the EPA test method, free: http://www.caslab.com/EPA-Methods/PDF/m-28.pdf Some of it gave me a headache reading through, but just so I have a better idea what I'm talking about, I read it. Not sure I FULLY understand all of it, but I get most of it. What it does NOT require is running fully closed, only that it runs at a buirn rate of less than .8 kg/hr, with the allowance that if a unit can't be made to burn that slow, it allows 2 tests at the next highest level. I interpret that to mean that whatever setting gets those goals achieved can be used, whether it's full closed or partially open.

I didn't look for the test standards for CSA.

My 1st experience with "EPA" tech. was on my cousins LOPI, aprox. 6ft. of single back pipe goin' into an old exterior masonry chimney maybe 15ft tall. Works like a charm! 1st time I witnessed the 2ndary burn tubes "gassing" I stood with me pie hole agape in amazement, that stove is still burnin' wood and burning it completely. A single draft control, I don't know what all it controls or shuts down when employed,,it must have "air wash" 'cause the glass/ceramic stays pretty clean.
Fast forward to last year. My best pal built a brand new stick built home, spray in insulation, single story,,air tight. I sang the praises of "EPA" 2ndary burn tubes, I also mentioned "CAT" stoves and admitted I'd not seen "CAT" stoves in action.
He picked up a new stove, air wash front door with the 2ndary burn tubes. A couple sticks of black pipe straight up into SS(with attic shield,stove installed to IN. code),,,3 sticks,,9ft of SS chimney thru the attic with a stick or two of SS to the rain cap. WELL seasoned hardwoods and his stove MAKES CHARCOAL!! LOTS OF IT!! I'm currently trying to convince him to use the outside air intake to see if any improvement is found. Thoughts,,ideas? His first thought was a GRATE to get air UNDER the fire!! I told him to save himself the trouble and 4-get the grate!! LOL,,
Looking into the 2ndary air is something I will tell him about, see if a mod to slow that down and create more primary air and improve his burning of coals..He currently gets 6 hour burn times at best with well seasoned hedge.
I find this to be a good thread and sure do hope yer new stove will be what yer looking for Spidey.

I think the hedge is a contributing factor there. Has he tried running on lighter/"midgrade" wood with the same results?

A tightly sealed house is the main reason for an outside air kit, and that might help as well. If it runs better with a nearby window cracked, by all means add one.

 

[Chris-PA]

Here's the EPA test method, free: http://www.caslab.com/EPA-Methods/PDF/m-28.pdf Some of it gave me a headache reading through, but just so I have a better idea what I'm talking about, I read it. Not sure I FULLY understand all of it, but I get most of it. What it does NOT require is running fully closed, only that it runs at a buirn rate of less than .8 kg/hr, with the allowance that if a unit can't be made to burn that slow, it allows 2 tests at the next highest level. I interpret that to mean that whatever setting gets those goals achieved can be used, whether it's full closed or partially open.

I didn't look for the test standards for CSA.

Thank you! That looks like the identical requirements as in CSA B415.

 

[greendohn]

I think the hedge is a contributing factor there. Has he tried running on lighter/"midgrade" wood with the same results?

yeah, he also burns ash,cherry,walnut and some hack berry which he burns while up and about with same results. I have tried to encourage him to not stuff it so full until bed time/goin' to work. I get lots of un-burnt charcoal in my OWB if/when I feed it too much wood and demand for heat is low..I've mentioned that about my stove as a reference,,he's/we are still on a learning curve with this stove..

A tightly sealed house is the main reason for an outside air kit, and that might help as well. If it runs better with a nearby window cracked, by all means add one.[/QUOTE]

Rite on,,it seems to draft okay, no smoke when door is open and hot flu. No need for open windows and sech,,The outside air is something I've read about here and suggested because it wouldn't cost much to try. The stove is in the attached, well insulated garage and he leaves the door open to the house to help dist. heat. His house is very tight and well insulated,,if draft were a problem I would have personally installed out side draft my self outta pocket. Our friendship goes back to the 70's, we're like brothers except we aint never had a feud! LOL! The option of outside air is an option on this stove and a requirement in some regions by "code", I believe. I'm just thinkin' this option may very well allow the stove to perform better as the option was "engineered" into the stove,,and I can't convince him to load less wood in the beast!! It seems to be a pretty good stove and he doesn't have the owners manual any more,,

Thanks for the reply.

 

[mooseracing]

I'm currently trying to convince him to use the outside air intake to see if any improvement is found. Thoughts,,ideas? His first thought was a GRATE to get air UNDER the fire!! I told him to save himself the trouble and 4-get the grate!! LOL,,

I use outside air and still get a ton of coals. I use a Napoleon 1400 that is supposed to heat a larger house, it works fine at about freezing temps. After that all I do is layer up, as when it is down in the single digits the house is in the low 50's running the stove all day. I'm going to a bigger stove to at least give me room to work with coals, more heat, and longer burn times.

I can't remove any brick since it holds the baffles up. Also the out of control burns in a high draft situation seem unsafe from my viewpoint.

 

[Whitespider]

Sorry… I was working on the road today.

Here's the EPA test method, free: http://www.caslab.com/EPA-Methods/PDF/m-28.pdf ...it does NOT require is running fully closed

Wow, I spent over two hours on the EPA website last weekend trying to find that, and you come up with it in a couple hours… my internet search skills obviously need some refining. I actually had that publication (in digital form) at one time but lost it when my work laptop crashed. Because I couldn’t find it, I went strictly on memory, and I was dead positive it required testing at the lowest possible setting. I even knew exactly where to find it… under the “Test Run Requirements” section. I quickly found it in your link by using my PDF reader search function for the words “lowest possible” in section 8.1.1.3.2. But it seems I either misread it before, or my memory is failing a bit, (or maybe I wanted it to read a certain way, and convinced myself that it did) because this is how it’s worded…

8.1.1.3.2 Evidence that a wood heater cannot be operated at a burn rate less than 0.80 kg/hr shall include documentation of two or more attempts to operate the wood heater in burn rate Category 1 and fuel combustion has stopped, or results of two or more test runs demonstrating that the burn rates were greater than 0.80 kg/hr when the air supply controls were adjusted to the lowest possible position or settings.

I was wrong… testing at lowest possible user setting is not required… but can be used for documentation purposes if needed…

My apologies to you WoodHeatWarrior.

 

[Whitespider]

BS...Enlighten me.

No... I will not... arguing with you over how I posted something verses how you read it adds nothing of value here.

 

[Whitespider]

greendohn and mooseracing,
I’d like to take this opportunity to personally welcome you guys to the Excessive Coal Makers Club.
Our small membership is slowly growing… and as President de facto I will soon be calling our first club meeting to elect proper officers.
I hope to see you then :hmm3grin2orange:

 

[Chris-PA]

I was thinking about it on the way home Spidey, and this thread has been worthwhile. I tried to get such a discussion going some time ago but it didn't take. I think we've actually made some progress in figuring out some fundamental issues of these types of stove that many may not have realized, and it makes a big difference in how they perform.

The next thing I want to try to understand is this coaling issue. It doesn't make sense to me that really high airflows through the top of the firebox (from primary to flue) would leave the bottom of the box so starved for oxygen that it coals up. However, you and other here are having a coaling issue. Short burn times I get, but this part I don't.

 

[Whitespider]

However, you and other here are having a coaling issue. Short burn times I get, but this part I don't.

I understand that...
Like I posted in response to Steve NW WI way back on page 4…

In fact, most of the time it don't even make sense.

 

[Chris-PA]

Of the people who are having excessive coaling, is there some common thread - how many are running flue dampers, what kind of flue height is involved?

 

[Whitespider]

Of the people who are having excessive coaling, is there some common thread - how many are running flue dampers, what kind of flue height is involved?

Let's add another question or two...
Where do you live? (general area is OK... looking for climate, elevation and whatnot)
And do you notice the problem (or problems) get better or worse with temperature (or other ambient conditions)?

 

[stihly dan]

Well actually I liked the write ups and what w-spider has done to to point out the possible deficiencies of the EPA stoves, as I am looking for another, and as a greenie, I thought these new EPA stoves may be the best thing... Now I don't know if one would be the best.

No the EPA stoves are great stoves. Much better than the old ones. You just have to undestand the application you need, and get one that fits. They are not the same. some have cats, some have overfire, some have both. There are down draft stoves, there are stoves with no overfire or cat. Like the harmen, Its kind of a maze that burns the smoke.(I don't know what to call that.) I wish this thread was out 2 yrs ago, would have helped in my fight with the stove. Which I never mentioned worked perfect in someone elses 1st floor.

 

[noodle]

I've fooled around making the secondary combustion air input adjustable on our F600cb. From the factory I don't believe secondary air is adjustable. If secondary air is cut off after the flammable gasses are burnt it is obvious that the bed of coals is burnt down faster. Stove top temperature also noticeably rises.

I believe a slight increase in efficiency is gained but it takes more adjusting and if the firebox is loaded with more wood on top of the coals and the secondary air is not opened back up of course secondary combustion suffers.

Del, I have the same stove as you do. Forgive my ignorance. what adjustments can be made aside from the obvious primary air on our stove? What kind of burn times are you getting on a loaded stove (down to usable coals)?

 

[woodchuck357]

I am chief wood supplier and stove "expert" for

six homes. The stoves range from a cast iron Chinesse copy of a "king heater" to a non-cat epa certified POS. No outdoor burners. The epa cert stove has been re-enginered to alow complete control of all air intake, plus air flow has been introduced under the fire bed to burn up the coals when they get to that excessive coaling stage. It doesn't operate automaticly, but it now makes heat when we want it to. And will coal up and smolder all night when we want it to.

By the way, the king heater copy will shut down enough to completly choke off a roaring dry wood fire.

 

[pennsywoodburnr]

Man, this thread is probably the most interesting one I've seen in a while. Can't wait to see what the outcome of whitespider's dilemma is. Keeping my fingers crossed that you find a solution man.

 

[Whitespider]

I wish this thread was out 2 yrs ago, would have helped in my fight with the stove. Which I never mentioned worked perfect in someone elses 1st floor.

Like I said, my brother's FIL, who gave me the stove, thought it was the greatest thing since sliced bread. According to him it made more heat, burned longer, and used less wood than any stove he'd ever owned before it... and he never had a coal build-up issue. He wouldn't lie about it, he ain't that type of guy (he was my boss for a short time before my brother and his wife took over the business)... he's a straight-up guy. Hearing him describe it, and how well it worked, you'd think he was talking about something different than he gave me. And, again like I said, he had it installed in a single story, flat-roof with a darn short chimney.

Now I wouldn't say that a tall chimney, or a basement installation would automatically be a problem with this stove or any other EPA design. The problem isn't the chimney, or the basement; the problem (I now believe) is an overdraft... and a taller chimney is just more likely to have more draft, especially in cold weather. In my case, with a tall, massive brick chimney running from basement floor up through the center of the house (always very warm), it has more draft than will be seen in most other installations... heck, it has more draft than any other I've ever had. Remember, it was originally designed for a big old coal-fired furnace around 1900.

Likely, if I would put both the primary and secondary air on separate controls, and continued using the flue damper, I could find the "sweet spot" where it would operate correctly... today. But tomorrow I'd have to find it again... and the next day... and the next. It would be a nightmare trying to keep up with changing atmospheric conditions, and changing firebox conditions as the fire burned down... and be a horror story during real cold weather trying to balance three controls. Like I've said, during warmer weather (say 35-40[sup]o[/sup] and above) the thing runs pretty darn good... heats for hours on just a few sticks, complete burns without excessive coaling, and will cause the wife to open doors. And again, like I said, I was very impressed during the early part of the heating season... our wood consumption was barely measurable during November. Heck, last night it was in the upper-30's, no wind, I loaded it about 3/4 full around 7:00 PM and closed the flue damper about 2/3's (in this weather I could go back to using the stove draft control)... this morning, 4:00 AM, 9 hours later, it's 26[sup]o[/sup] outside, the house is 70[sup]o[/sup] (the steel was uncomfortably hot to the touch) and there was just a few coals in the back, just enough to easily get a fire going... and likely the wife won't add any more wood all day, as temp are supposed to be in the upper 30's again. In my book, that's exceptional performance, but it don't remain exceptional as outside temps fall. When it gets cold enough, and the draft increases, the thing just flat quits heating and starts making charcoal... I mean stops heating, I can lay my hand on the bare steel.

So anyway, I'll move it out in the shop (which is really and old, drafty, two-stall, detached garage). I've had a couple of barrel stoves in there (nothing now) and the chimney is sort'a a cobble-job... uninsulated pipe running out a window and 10-foot up the back wall. Draft has always been a problem at cold start-up, and not overly great when running... maybe this EPA stove will like that better. Don't worry, if it don't run right I won't be blaming the stove; I know I have "poor" draft in there and nothing has run all that great... but maybe, just maybe, if these stoves really are design to run on the lowest possible draft conditions (as that article says) it might just love my shop with its short, cold chimney.


addendum; I want to add that my whining, complaining and bad-mouthing of EPA stoves this winter has been driven by pure frustration. I had no plausible explanation for what was going on, so I simply lashed-out at the object of my frustration and anger. Now that I actually have an explanation that "fits", that makes some sort of sense, my frustration level is several octaves below what it was... a certain amount of objectivity and reason has returned.

 

[Chris-PA]

I still don't understand the coaling in high draft conditions and I still want to explore that. I guess the most basic thing is what makes coals? I always thought it was burning without enough oxygen - that's how they make charcoal, and my stove only makes a lot of coals when it's closed down too far.

Is it really possible to have so much draft that the air coming out of the primary/airwash and secondary outlets bypasses right over to the flue opening, and leaves the bottom of the firebox starved for air? I just can't buy that yet - it's a small box and I can't see the air stratifying and becoming stagnant, it would have to mix plenty in there.

Perhaps it's better to think of it as a wood gasification system, which it is. Is it getting the wood so hot that the volatile stuff is all cooking out early leaving only coal? But I still don't see why they won't burn up with lots of airflow.

Are these coal beds really buried under ash? Maybe the burning conditions early on are making a lot of ash and that is sealing off the wood below it? What makes a lot of ash?

EDIT: Maybe that is it - with no limit on secondary air the wood at the top of the firebox is incinerated to ash, which buries the lower wood, and then that just smolders. With my stove both primary and secondary are limited so they stay more in proportion.

 

[Whitespider]

I had a hard time understanding it also WoodHeatWarrior, until I put the newspaper “smoke bomb” inside the pedestal where the air enters. I could watch the smoke reverse direction and head out the flue well before it made it to the bottom of the box… the overdraft just makes the flue a huge vacuum cleaner. By changing the stove draft control, or the flue damper, I could make the smoke go a little lower, or higher, in the box before it reversed… but it never made it to the coals. I played around with it for most of a morning and just couldn’t get it to work. In my case the draft is so strong that no matter how I tweak, the draft just over powers the inlet… I can’t get the relationship between intake and exhaust to balance properly.

When it gets really, really cold and my draft goes wild… it pulls the incoming air out before it can get to the fire, and sucks any heat being made right along with it. And pulling the heat out just compounds the problem… it becomes a charcoal maker. It doesn’t matter where things are set; the relationship of incoming to vacuum can’t be balanced. The only way I can see to change that (and I’ve tried everything else mentioned, plus more) would be to open the holes to the primary air (not the main hole where air enters the stove intake system, but the holes where air actually enters the firebox chamber) to increase velocity/volume in relation to the draft (at any given setting)... but heck, that could make things worse. The problem, and my fear is, the stove would way over-fire… especially during warmer weather with a somewhat reduced draft. Another option would be to place a restriction in the top of the chimney… but then there’s the possibility of smoke filled house during times of reduced draft. And besides, right or wrong, I have an appliance shared chimney… I have to be extremely careful about chimney modifications (admittedly, that does place limits on my options to some degree).

I should add... what few coals are kept live is only because of the "pilot", or "boost" air because when i plugged that problem got much worse... I found complete unburnt splits under the coal bed.

Maybe a shorter explanation would be that the extreme over-draft is turning my firebox into a vacuum chamber.

 

[brenndatomu]

Like I said, my brother's FIL, who gave me the stove, thought it was the greatest thing since sliced bread. According to him it made more heat, burned longer, and used less wood than any stove he'd ever owned before it... and he never had a coal build-up issue. He wouldn't lie about it, he ain't that type of guy (he was my boss for a short time before my brother and his wife took over the business)... he's a straight-up guy. Hearing him describe it, and how well it worked, you'd think he was talking about something different than he gave me. And, again like I said, he had it installed in a single story, flat-roof with a darn short chimney.

Now I wouldn't say that a tall chimney, or a basement installation would automatically be a problem with this stove or any other EPA design. The problem isn't the chimney, or the basement; the problem (I now believe) is an overdraft... and a taller chimney is just more likely to have more draft, especially in cold weather. In my case, with a tall, massive brick chimney running from basement floor up through the center of the house (always very warm), it has more draft than will be seen in most other installations... heck, it has more draft than any other I've ever had. Remember, it was originally designed for a big old coal-fired furnace around 1900.

Likely, if I would put both the primary and secondary air on separate controls, and continued using the flue damper, I could find the "sweet spot" where it would operate correctly... today. But tomorrow I'd have to find it again... and the next day... and the next. It would be a nightmare trying to keep up with changing atmospheric conditions, and changing firebox conditions as the fire burned down... and be a horror story during real cold weather trying to balance three controls. Like I've said, during warmer weather (say 35-40[sup]o[/sup] and above) the thing runs pretty darn good... heats for hours on just a few sticks, complete burns without excessive coaling, and will cause the wife to open doors. And again, like I said, I was very impressed during the early part of the heating season... our wood consumption was barely measurable during November. Heck, last night it was in the upper-30's, no wind, I loaded it about 3/4 full around 7:00 PM and closed the flue damper about 2/3's (in this weather I could go back to using the stove draft control)... this morning, 4:00 AM, 9 hours later, it's 26[sup]o[/sup] outside, the house is 70[sup]o[/sup] (the steel was uncomfortably hot to the touch) and there was just a few coals in the back, just enough to easily get a fire going... and likely the wife won't add any more wood all day, as temp are supposed to be in the upper 30's again. In my book, that's exceptional performance, but it don't remain exceptional as outside temps fall. When it gets cold enough, and the draft increases, the thing just flat quits heating and starts making charcoal... I mean stops heating, I can lay my hand on the bare steel.

So anyway, I'll move it out in the shop (which is really and old, drafty, two-stall, detached garage). I've had a couple of barrel stoves in there (nothing now) and the chimney is sort'a a cobble-job... uninsulated pipe running out a window and 10-foot up the back wall. Draft has always been a problem at cold start-up, and not overly great when running... maybe this EPA stove will like that better. Don't worry, if it don't run right I won't be blaming the stove; I know I have "poor" draft in there and nothing has run all that great... but maybe, just maybe, if these stoves really are design to run on the lowest possible draft conditions (as that article says) it might just love my shop with its short, cold chimney.


addendum; I want to add that my whining, complaining and bad-mouthing of EPA stoves this winter has been driven by pure frustration. I had no plausible explanation for what was going on, so I simply lashed-out at the object of my frustration and anger. Now that I actually have an explanation that "fits", that makes some sort of sense, my frustration level is several octaves below what it was... a certain amount of objectivity and reason has returned.

You have probably already talked about why you haven't tried this before, and I think it was stihly dan that suggested it before too, but I strongly suspect that a barometric draft regulator would help immensely. Limit your continually varying draft to a set # irregardless of weather conditions, basically, turn your tall chimney into a short one. Wouldn't be difficult or expensive to do this, it'd prove or disprove your current theory...

I know for me, I was really hesitant to install one (BDR) But decided to install everything as per Yukons instructions, change it later if I didn't like it. Well, after living with a BDR on a wood furnace for a couple years now, I'm a believer. All the hype about cooling the chimney too much, making creosote, etc, have proved unfounded for me. It just works...

Just as an FYI, I'm running -.02 to -.04" WC most of the time, the Yukon runs real sweet there, if I hold the BDR shut, my draft shoots up over -.10, even -.15" WC in a heartbeat. (I have a Dwyer Mark II manometer permanently mounted) That's with 30' tall 8" chimney.