How soon do you turn the air down

[thinkxingu]

Secondary burn means that the stove is burning the gases released from the burning process instead of sending them up the chimney. Feat from what would otherwise be wasted? Sounds good to me (like a bunch 'a wood found on the side-a the street!).

S

 

[Green Energy]

This is off the topic but is the secondary burn a good thing to go for or am i on the wrong page. To me i think that's what the epa wants and its very cool to watch.

Actually, I think you are right on target - strong secondary burn after you turn the air down confirms that the fire is hot enough to have the primary air turned down. Strong secondaries = clean burn/high efficiency = should equal no smoke out the chimney

About 45 minutes ago, I went from almost a cold start (150 F stove top, a couple embers buried in the ash) to strong secondaries in about 20 minutes. I turned the primary air down to 50% at about 15 minutes, corner temp was ~ 300 F, but IR reading at the center was 450 F. Was able to turn the air to 10-20% at 17 minutes, then completely off at 20 minutes. Sometimes I go below 50% a little too quick, but I just go back to 50% for a couple minutes.

As others have already stated, some stoves heat differently. There is a lag in exterior surface temp with cast iron, and especially with stone.

After 50-60 minutes, stove corner is at 550 - 600 F, secondaries are in blast furnace mode, primary air has been completely shut down for 30-40 minutes. After some struggling my first winter with this stove, I think I am getting it down. If you have a good setup, it is then in good well seasoned wood, and building a good top-down fire.

 

[corey21]

Thank you all i was just making sure i was on the right track.

 

[Soadrocks]

I have the Jotul Castine and a mixture of hardwoods and I always wait til it hits around 575 stovetop...wait 15 minutes, drop it down to 50% where it usually is around 650 degrees, and then 10 minutes later to 95%. Is this wrong? We always get a beautiful secondary show.

 

[dkf5]

Hi Corey, I have the same stove. I leave the door cracked a bit and the lever in the front wide open. Once the temps start to get 350-400 degrees then I begin to close it down. We run it usually between 400-500 degrees. Let it burn down and add to it when needed. Runs beautiful. Donna

 

[corey21]

Hi Corey, I have the same stove. I leave the door cracked a bit and the lever in the front wide open. Once the temps start to get 350-400 degrees then I begin to close it down. We run it usually between 400-500 degrees. Let it burn down and add to it when needed. Runs beautiful. Donna

That's how mine runs but i can shut the air all the way at 400 and keep the secondaries going.

 

[burleymike]

With my Osburn burning pine I close it down to 50% once the fire looks good. I can tell it is "good" when the flames are dancing around the secondary tubes and the tubes are starting to glow. Between 5 and 10 min at 50% I can turn it down all the way or nearly all the way and it will cruise between 450 and 700 depending on how windy it is and how much wood I load in to it.

I did learn that when loading on top of hot coals I can close it down quite quickly and it will keep burning good and if I let it go very long it will be burning very hot and fast. I think if I had hardwood I would have to wait longer to shut it down.

The other morning I put in a couple splits that were covered with pitch. Once they started (5 minuets) it was smoking thick black smoke like oil burning. I discovered that with it wide open I had black smoke coming out the chimney I tried cutting the air to about 40% and the secondaries fired right up and the black smoke completely disappeared. I think with it wide open the fire was just burning too fast and taking all the smoke/soot/heat up the chimney.

 

[Ken45]

In my limited experience, I would not judge my stove by other stove's temperatures. I've never been able to get above 450-500 degrees no matter how I load and/or run the stove...and that varies as to where the thermometer is placed. Besides, who knows how accurate those thermometers really are? However, at "500 degrees", the stove is really cranking out the heat! It must be equivalent to some of the 800 degree readings that others are getting.
I don't have the flue pipe option, which is probably more reliable, since I have insulated pipe starting at the collar. I don't put the thermometer on the stove top since I believe the fan affects it's reading.

Cutting back on a time schedule will vary greatly depending on:
-- how hot the coals are and how big of a coal pile
-- the size of the wood
-- the wood species
-- how well seasoned it it.

Bottom line, I kind of know when I get a good secondary burn my thermometer reads around 350, but I'll often get down and make sure I have a good secondary going.

The more experienced hands here can tell me if I'm all wrong

Ken

 

[firefighterjake]

Random thought . . .

Interesting . . . some of us just go by the way the fire looks before we start to adjust the air, some of us go by the stove top thermometer and some of us go by the flue thermometer and some of us go by a combination. For me, I mostly rely on the flue thermometer . . . and to answer Corey's original question . . . I start cutting back the air at 400-450 degrees F as shown with a probe style thermometer. I've had good luck in doing so as it is rare that I end up with a fire that starts to suffocate and smolder . . . but to each their own . . . as you can see from the many answers there are more than one way to skin this proverbial cat.

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

Sustained secondaries . . . sounds like you're doing everything well. Keep up the good burning.

 

[corey21]

Random thought . . .

Interesting . . . some of us just go by the way the fire looks before we start to adjust the air, some of us go by the stove top thermometer and some of us go by the flue thermometer and some of us go by a combination. For me, I mostly rely on the flue thermometer . . . and to answer Corey's original question . . . I start cutting back the air at 400-450 degrees F as shown with a probe style thermometer. I've had good luck in doing so as it is rare that I end up with a fire that starts to suffocate and smolder . . . but to each their own . . . as you can see from the many answers there are more than one way to skin this proverbial cat.

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

Sustained secondaries . . . sounds like you're doing everything well. Keep up the good burning.

Thank you Jake.

 

[Ken45]

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

And less creosote, very important IMO.

Ken

 

[corey21]

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

And less creosote, very important IMO.

Ken

The glass stays clean to.

 

[kmachn]

So, it sounds like there are a variety of methods. I'm a newb to using a wood stove, and have been experimenting over the last week. Learning a lot here on hearth.com about secondaries, etc. Personally, I like the idea of using a thermometer because I'm kind of a numbers guy and I like to quantify everything. So for those who are using stove top temps, how should I manage my Quad Cumberland Gap? having a cast-iron top, it sometimes takes longer to heat up and there is an air space (where the blower would go if I had one) about an inch above the steel firebox top. Would it be better to use an IR gun on the firebox top to measure ~500 degrees, or would it be better to use a stove top thermometer on the cast-iron top? The cast-iron top seems like it would carry a different level of reliability, taking longer to heat up than the actual steel firebox top.

However, if I watch the fire before shutting it down, it seems that it is sometimes too early and the secondaries seem to die out more quickly. With all of the suggestions in this thread, I'm thinking a combination and practice is the answer. But I'd love to hear suggestions from those with a cast-iron stove top and temperature recommendations.

 

[oldspark]

Random thought . . .

Interesting . . . some of us just go by the way the fire looks before we start to adjust the air, some of us go by the stove top thermometer and some of us go by the flue thermometer and some of us go by a combination. For me, I mostly rely on the flue thermometer . . . and to answer Corey's original question . . . I start cutting back the air at 400-450 degrees F as shown with a probe style thermometer. I've had good luck in doing so as it is rare that I end up with a fire that starts to suffocate and smolder . . . but to each their own . . . as you can see from the many answers there are more than one way to skin this proverbial cat.

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

Sustained secondaries . . . sounds like you're doing everything well. Keep up the good burning.

Jake, that is a really low flue temp to reduce the air is it not, (probe) that would be like me doing it at 200 to 250.

 

[corey21]

Random thought . . .

Interesting . . . some of us just go by the way the fire looks before we start to adjust the air, some of us go by the stove top thermometer and some of us go by the flue thermometer and some of us go by a combination. For me, I mostly rely on the flue thermometer . . . and to answer Corey's original question . . . I start cutting back the air at 400-450 degrees F as shown with a probe style thermometer. I've had good luck in doing so as it is rare that I end up with a fire that starts to suffocate and smolder . . . but to each their own . . . as you can see from the many answers there are more than one way to skin this proverbial cat.

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

Sustained secondaries . . . sounds like you're doing everything well. Keep up the good burning.

Jake, that is a really low flue temp to reduce the air is it not, (probe) that would be like me doing it at 200 to 250.

My stove runs at 450 probe and that's with secondary's.

 

[firefighterjake]

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

And less creosote, very important IMO.

Ken

The glass stays clean to.

Cleaner burn = less creosote AND clean glass

 

[firefighterjake]

Random thought . . .

Interesting . . . some of us just go by the way the fire looks before we start to adjust the air, some of us go by the stove top thermometer and some of us go by the flue thermometer and some of us go by a combination. For me, I mostly rely on the flue thermometer . . . and to answer Corey's original question . . . I start cutting back the air at 400-450 degrees F as shown with a probe style thermometer. I've had good luck in doing so as it is rare that I end up with a fire that starts to suffocate and smolder . . . but to each their own . . . as you can see from the many answers there are more than one way to skin this proverbial cat.

Secondary burns . . . are good and desired. As mentioned the combustible gases that would normally go up the chimney are now being burned = cleaner burn and more heat in the second burn.

Sustained secondaries . . . sounds like you're doing everything well. Keep up the good burning.

Jake, that is a really low flue temp to reduce the air is it not, (probe) that would be like me doing it at 200 to 250.

Nope . . . it's close to the low side . . . but when I start shutting down things typically the temp will go up a dite . . . although truthfully I like to start shutting things down better when I'm at 450 degrees F or so.