A couple questions on non-cat secondary burn

[southbalto]

I've read about some amazing burn times with larger epa stoves here on hearth.com. I hear about englander 30 and blaze king owners getting 12-16-20 hours of good heat.

The operation of the newer EPA stoves is somewhat new to me. As I understand it, the secondary burn occurs when the fuel is heated to the point where it begins to off gas. This gas is then mixed with the oxygen that introduced towards the top of the firebox which results in the secondary burn. When operating these larger stoves how is the secondary burn managed? Once the stove is up to temperature (400+) (which I imagine happens within the first hour) doesn't all the off gassing occur within the next say 2-4 hours? Thus the stove has the secondary burn engaged for less than 5 hours? Is there a way to damp down the stove so that you get a longer period of secondary burn time?

I'm still in the process of learning my new castine. It's my goal to run the stove hard early (run up to 650) then let it cruise for 4-5 hours back down to 300 or so. To burn efficiently should I always try to get a good secondary burn going? Sometimes I just want to maintain a 350-400 stove top by throwing in a split over a coal bed. When I do this the split burns well but It usually doesn't result in a row of blue jets up top. Is running the stove this way a problem/inefficient?

Thanks hearth.com

 

[woodzilla]

in my opinion... you have to run the stove differently for different conditions. it would be more inefficient to burn large hot fires and dump extra heat through a door or window as you become uncomfortable. burn as hot and as much as you need to but no more. just remember that you will have to sweep your pipe/liner more often as you move away from full tilt burning. again, my 2$ (inflation adjusted)

 

[soupy1957]

I'm still a relative "newbie" at burning wood in my new EPA stove, but I believe the damper being closed down "gradually" has something to do with enticing the secondary burn. I've not achieved (or learned) the full secondary burn yet, and am still getting the hang of it. I can get the back row of secondary burn holes to light up but I've yet to see the front row kick in............and I burn HOT

-Soupy1957

 

[southbalto]

Oh I agree. You certainly have to run the stove differently based on what you want out of it.

I'm still at a loss as to the secondary burn times though. It seems all or nothing. You get up to temp and the load off gasses over 3-4 hours then you are in the coal stage. With bigger stoves do you get longer secondary burn times? Is there any way to control the off gas period? Seems an use it or loose it type thing.

 

[summit]

get it goin balls to the wall, wait for a good thick base of coals and full pieces falling apart. then stuff it full as possible and shut 'er down.

 

[snowtime]

Your correct secondary burn is burning the off gasses by introducing air through the baffle system. I think people get to taken up with trying to maintain the secondary burn. Just get your stove up to operating temp and then turn air down to level you need to be comfortable. If you are getting to hot then put less wood in stove and let the stove temp go lower before reloading. You might have to leave the air open a little longer to get it going again but its a good way to keep the temp down.
It is also effected by how easy it is to run your stove. My T6 starts easy from any temp as long as there are even the hint of coals and I do not wait around for a certain temp. I just see that the splits have caught and then I turn the air down. The stove will go to 500 or so but with normal loading goes to 800 or so.

This is all about shoulder season as during normal operation I do not let the stove cool and I put in full loads of course.

 

[bluefrier]

A wood fire burns in three stages. Heating and evaporation, combustion, and charcoal. Yes, the first part of the burn will be the most intense in a non-cat stove. Even a big stove will flame for a couple hours and then cruise in the charcoal stage. Sounds like you're doing ok to me.

 

[rdust]

I get about two hours or so of good secondary burn then the stove settles in. Don't get caught up trying to get the tubes pouring out flames, you can still have secondary combustion without the tubes going full tilt. The ghostly or unnatural looking flames are also secondary burn flames.

Also dry wood is key, if the wood is dry you can turn it down and still burn clean without the stove going full tilt.

 

[Hogwildz]

Secondary seems to vary by wood, temp, etc.
I just made my first attempt at a video, with my cheapo Sanyo digital camera.
But here is a link. Not the best video, or best representation of secondaries, but here it is.
I get secondaries for a few hours till the coal stage.

http://www.youtube.com/watch?v=BVYa2QyhD6o

 

[BrotherBart]

The only time I see the Holy Grail of hearth.com, flames blasting out of the burn tubes, is when I am stuck with nothing but medium and small splits for a night burn. I load the 30-NC between eight thirty and nine o'clock by dragging the coal bed to the front 12 inches or so of the firebox and placing three or four big ass splits N/S on it. Once the out gassing of the part of the splits sitting on the coals is done I level it out at five hundred degrees stove top and go to bed with a stove producing nice flames between the splits and none of this blast me to the moon stuff from the burn tubes. At seven thirty or eight the next morning I get up to a warm house and the beloved coals to restart while the coffee brews.

Why anybody wants to send one third of their fuel up the flue in a blast of "secondary burn" is beyond my comprehension. Not to mention it is an ugly fire. Nice flames look better. :coolsmirk: If I wanted that stuff I would put a kerosene torpedo heater in my living room.

 

[Hogwildz]

The only time I see the Holy Grail of hearth.com, flames blasting out of the burn tubes, is when I am stuck with nothing but medium and small splits for a night burn. I load the 30-NC between eight thirty and nine o'clock by dragging the coal bed to the front 12 inches or so of the firebox and placing three or four big ass splits N/S on it. Once the out gassing of the part of the splits sitting on the coals is done I level it out at five hundred degrees stove top and go to bed with a stove producing nice flames between the splits and none of this blast me to the moon stuff from the burn tubes. At seven thirty or eight the next morning I get up to a warm house and the beloved coals to restart while the coffee brews.

Why anybody wants to send one third of their fuel up the flue in a blast of "secondary burn" is beyond my comprehension. Not to mention it is an ugly fire. Nice flames look better. :coolsmirk: If I wanted that stuff I would put a kerosene torpedo heater in my living room.

Bah!
I like blast and long burn, so there...............
Now if I could only score some cid, so I could watch it for hours while drooling on myself and not even knowing it. :bug:

 

[southbalto]

Thanks for all the replies.........

BrotherBart....I'll be down your way this week. 28 and lee highway Tues-Fri. I hope VDOT got things cleaned up.

 

[BrotherBart]

Thanks for all the replies.........

BrotherBart....I'll be down your way this week. 28 and lee highway Tues-Fri. I hope VDOT got things cleaned up.

Good luck. I spent 18 years getting into and out of Fairfax during and after snow storms. My sympathies are with you. I will be hanging out in front of the stove Tue.-Fri.

Sometimes my tracks were the first ones through the snow at five in the morning on the back roads of Prince William County. I do not miss it at all.

 

[PapaDave]

Good video, Hog.
How ya feelin? Better every day, I hope.

 

[southbalto]

Thanks for all the replies.........

BrotherBart....I'll be down your way this week. 28 and lee highway Tues-Fri. I hope VDOT got things cleaned up.

Good luck. I spent 18 years getting into and out of Fairfax during and after snow storms. My sympathies are with you. I will be hanging out in front of the stove Tue.-Fri.

Sometimes my tracks were the first ones through the snow at five in the morning on the back roads of Prince William County. I do not miss it at all.

It's not so bad. I wouldn't want to commute in full time though.

I'm near Baltimore and I usually come in the back way through Frederick/Leesburg. I avoid 495 at all costs.

 

[Hogwildz]

Good video, Hog.
How ya feelin? Better every day, I hope.

Aye, feeling pretty good.
The area is still numb, but I have a constant phantom itch going on. But when I scratch I can't feel the scratching or the itch spot with my fingers.
I feel it, but can't find it or scratch it. Driving me nuts LOL.
I bought a new microwave yesterday, and had to lift it myself. Its only 37 lbs, and didn't feel like a strain or nuttin.
Still trying to stick to the doc's 25 lb limit when I can. Last thing I want, is to do this all over again.
I'm sure I lifted a bit more when loading my wood bins last week. But It has to be done. And I am the only one here to do it.
Other than that, I am consciously trying to adhere to the rules.
I'm hoping to be processing my wood for next year, next month, before the insects and gnats are out chewing away at me.

 

[southbalto]

Free managers reception at the Embassy Suites Dulles from 530-730 daily.

Liver is going to be working overtime.

 

[Hogwildz]

Free managers reception at the Embassy Suites Dulles from 530-730 daily.

Liver is going to be working overtime.

If they have that in the Summer, BB is gonna have to bring a pick up to come get me & my bike

 

[southbalto]

Free managers reception at the Embassy Suites Dulles from 530-730 daily.

Liver is going to be working overtime.

If they have that in the Summer, BB is gonna have to bring a pick up to come get me & my bike

lolz

 

[North of 60]

Secondary seems to vary by wood, temp, etc.
I just made my first attempt at a video, with my cheapo Sanyo digital camera.
But here is a link. Not the best video, or best representation of secondaries, but here it is.
I get secondaries for a few hours till the coal stage.

http://www.youtube.com/watch?v=BVYa2QyhD6o

Not a bad video shoot for a Yeti. :ahhh:

 

[firefighterjake]

Just a technical point . . . most Englanders are now using secondary combustion tech . . . older Englanders and present-day Blaze Kings used cat technology.

I think you've pretty much summed up what secondary burning tech is all about . . . and how to achieve it . . . get the woodbox good and hot and then start dialing down the air until you start seeing either the Northern Lights flickering in the top third of your firebox or it looks like a portal to Hell has just opened up in your woodstove.

For me my goal is typically to achieve secondary burning -- cleaner burn and more efficient burn . . . besides I hate the idea of letting that extra smoke go up the flue when I could be burning that and isn't two of anything better than one . . . I figure a second burn is a good thing.

If I'm just trying to keep a fire going without a lot of heat I will do one of two things . . . I may add a split here or there to keep the fire going . . . but I also open up the air and let the split burn strong . . . this way the temps are up in the flue to help reduce creosote production and it burns down any coals which may have accumulated from longer burns. If I want a bit more heat, but not a great amount of heat, I will do a small reload and/or use wood that is not a high BTU wood . . . I may still get a secondary burn . . . but the heat is not as intense or sustained for as long.

 

[bokehman]

Its pretty simple really, you get secondary combustion when the air delivered by the primary is not sufficient to burn all the woodgas being released. Since on an EPA stove it is impossible to close the primary beyond a certain point there will always be enough primary air for a small fire so usually little on no secondary combustion will be visible. On the other hand if you get the same stove loaded to the gills, once the fire gets going and the primary is closed the secondary burn will be pretty active.

Here's what mine looks like with a small load. Note primary air is closed but is still almost enough to burn all the woodgas. A small amount of secondary can be seen above the baffle. With more wood the secondary would be much stronger than the primary. For me secondary burn almost never lasts longer than about an hour and a half.

 

[craigs]

Why anybody wants to send one third of their fuel up the flue in a blast of "secondary burn" is beyond my comprehension. Not to mention it is an ugly fire. Nice flames look better.

Some of us just get to see the same black box whether it's hot, cold, or out of control.