Secondaries after 5 minutes, can I reduce air?

[WarmBluthner]

Yesterday I reloaded the lukewarm stove. Little coals were remaining but enough to restart.

In a short time I had good flames, not only leaking from the logs but also appearing round the burn tubes.

Now I said to my son, "as there is a nice blanket af fire in the ceiling of the stove, all smoke will burn". We went outside and there was no smoke.

So although the stovetop bearly read 200 I turned the air down to 1/2 and the fire slowed down a bit, but still seamed to burn clean and grow very slowly.
I also reason that when I turn down primary air I reduce outgassing, so less burnable gases (creosote forming) , I move air injection from bottom of the fire to the top, so there is more air available for secondaray burning.

It took over an hour to get to 400. This is an Oslo so it takes long but can be done in 30 minutes with softwood and a lot of kindling. After 5 hours all wood consumed and enough coals to restart. I han the stove half full.

I'm aiming at a few effects here:
1. Reduce the amount of heat loss through the chimney at startup so more heat for us
2. Less risk, when you leave the air open and forget you could be in for a surprise
3. It seems this way the fire eats its way through the firebox instead of starting everywhere at the same time. I notice completely untouched wood in the back after 90 minutes.

That said, I realise that my stack will take a long time to heat up and although the wood is kiln dried and the fire seems smokeless I will probably take a risk here?

 

[Sully]

That happens to me sometimes as well. I see the secondaries all ready going after a load up, I've shut it down and the heat does not go. I new to this but unless I let the heat build with air open, than half way than close the stove top takes a long time.
From what I've learned on here I have been letting temp get up before I shut air down. At least have all the wood charred and good flames going.

 

[Nick Mystic]

I've had this same experience with my Jotul F600. However, for me it takes quite a lot of adjustment of my primary air control to keep the fire going well if I try to dampen it down too much too soon. It depends a lot on how hot the stove is to begin with and how solid a hot coal base I'm working with. On a cold start up it's nearly impossible to lower the primary air much beyond half way, regardless of whether or not the secondaries are firing off, and still manage to get a fire to keep building in the stove.

 

[Coog]

I say let the stove get hot before you bring the temp down. I had my air adjustment reset after I purchased the 7100. I couldn't modulate the air intake low enough. Now I can get the temp up to 800 if I want to (try not to) before I cut the air back and keep control of the fire.

I have never operated a cat stove but with a non-cat, to minimize creosote build up, it is best to get a small fire hot than to suffocate a large fire. Now with a BK, as I hear all of the time on this forum, those things can burn low and slow and require less hand holding.

The Netherlands climate is moderate?

 

[aansorge]

It is always a trick to get an EPA stove to burn just right but it becomes second nature after awhile. The more you use your stove the better you can sense when the stove is ready to be turned down. To early and you get poor heat production. Too late and the load lasts 1/2 as long as it should.

Still, they put out great heat and when burned correctly, generate basically 0 creosote.

 

[WarmBluthner]

In the Netherlands its around 40 (6 celsius). Right now. But a couple of days ago there was a 70 mph storm. That cools the house a lot.

 

[Hogwildz]

I'd let it run a bit longer before shutting her back. I think your will find the secondaries die out shortly after closing it down and the temp drop inside the stove.
I usually wait about 15 mins after reload on a lukewarm stove, then cut the air back to 1/2, then maybe another 10 mins then shut her down and let her do her thing.
5 mins just seems like not time enough for the wood to get charred and ablaze enough to cut it back down.

 

[begreen]

In the Netherlands its around 40 (6 celsius). Right now. But a couple of days ago there was a 70 mph storm. That cools the house a lot.

I read about that storm. It was huge and very powerful.

 

[WarmBluthner]

A very big tree went down around the corner.

If I had room I would go fior the wood

 

[aaron1]

In my limited experience it seems that this is highly variable depending on the coals and the wood type, dryness, and size but your case seems quite extreme! Just tonight I did a reload onto a thick, hot bed of coals. The stove was at around 325 F on the front right stovetop. I had it open full for a couple minutes to get it going strong, but I noticed the secondaries were lighting off almost immediately after reload!! I then cut back to 3/4 for a minute or 2, then down to 1/2 for a couple minutes. The stovetop was only at around 400F, and I was able to go down to 1/4 for a couple minutes and then to low draft. She rose us to 460F and just sat there with full secondaries. I usually don't get great secondaries until the stove is hotter than that, but I noticed the front left corner was a lot hotter than the front right, maybe 560F, so maybe that had something to do with it.

I'm wondering if it's better to look at the flames and if there's smoke coming from the stack rather than thermometer when dampering it down. I set up a camera looking at my chimney so I can monitor smoke from my laptop, so I am getting to know how long I have to burn at each draft setting to get no smoke. I would think that is the key determinant on whether you are dampering down the draft too fast. I try to go in stages of 1/4 draft down to zero now, and it seems to work a lot better with no smoke at each stage. At first, I wanted to damper it down faster to "save" the energy of the wood, but I wound up just putting more of the energy up the chimney as smoke! It's better to put heat up the chimney than smoke!! It varies a lot in terms of time and stove temp, but the flames seem to look similar each time I'm realizing. I never would damper it down with wood that hasn't been charred at all; it just wouldn't be ready. It's possible that your stovetemp was much higher on another corner of the stove and that is why secondaries took off so easily. I also find I don't always see smoke unless I go up and look out of the skylight in my roof which is only 15' or so from the window as opposed to from the ground where it is over 35' to the top! You may be putting out a fine, small amount of smoke and not know it.

 

[DBoon]

If I'm really motivated, it's really cold outside, and I've just re-loaded with 50% or more of hickory, I'll turn the air down early (at 350 or 400) and try to keep the fire from running to where it really wants to go with the hickory (650 degrees stovetop). If I get it right, I can get it to cruise at about 550 degrees for an hour (secondaries firing nicely), and then it will kick into a turbo mode and go up to 600 to 625 degrees for about another 45 minutes before settling back down in the 500s and then gently lowering.

It beats 700 degrees for an hour if I am five minutes too late on the air adjustment....

 

[aaron1]

DBoon, this is awesome information! I'm new to burning the Jotul F500 Oslo, and I think it would be similar to your stove in this way. I loaded it full of dry Elm one day after building a hot bed of coals and turned it down all the way a little too late. I was amazed that it went up to 600 really fast, sat there awhile and then just kept going up to 675! If I had known how it worked a little better, and had known how to watch the flame pattern better, I would have dampered it down sooner. I'm sure it would have sailed at a lower temp then maybe went up to 600-625 for a longer period. As it was, the secondaries ripped for at least 90 minutes.

 

[xman23]

DBoon, this is awesome information! I'm new to burning the Jotul F500 Oslo, and I think it would be similar to your stove in this way. I loaded it full of dry Elm one day after building a hot bed of coals and turned it down all the way a little too late. I was amazed that it went up to 600 really fast, sat there awhile and then just kept going up to 675! If I had known how it worked a little better, and had known how to watch the flame pattern better, I would have dampered it down sooner. I'm sure it would have sailed at a lower temp then maybe went up to 600-625 for a longer period. As it was, the secondaries ripped for at least 90 minutes.

Oslo guys, be careful when you close off the air all the way. If you slide it to fast it over travels and lifts up opening up a air path. You can look at it when you open the dog house to lube the slide.

 

[Elle]

Oslo guys, be careful when you close off the air all the way. If you slide it to fast it over travels and lifts up opening up a air path. You can look at it when you open the dog house to lube the slide.

what is this doghouse, lube and slide you speak of? *trying not to laugh too hard* I think I know what you mean by the slide-the air thingy? What is the doghouse and where might I find it? My air thingy does seem to stick a tad...or at least it doesn't seem to glide. Also there seems to be A LOT of play in the lever. Thanks

 

[aaron1]

I don't care about the play; I just push it farther to the right than I need to then come back to the same position to the left (when it is tight and engaged) to know if I am in the same position again. xman23, I don't really understand what your post means. Can you explain it more fully (assume we are idiots!)

 

[cableman]

What are you guys stack temps just above the stove once the secondaries are all fired up? I cant seem to keep mine down and they go as high as 700 then drop some.

 

[aaron1]

I can't measure my stack temp, as my fireplace opening is as tall as the stove. I guess i could remove the stove and reach up and put in a probe, but i'm not going to do that until next year if ever. I think fire fighter jake could give you some good info. on this.

 

[cableman]

This was off 4 splits of 17% oak, a piece fell so it flared a little more and looked like this. Secondaries lasted an hour stove top in spots were over 450 cause my temp gun reads hi lol. Some spots read 420 or so. After secondaries were done for a little stove dropped to 350 and stack to 500. Maybe the stack therm just dont drop quick enough!

This was the other night with same temps

 

[aaron1]

Isn't the stack temp supposed to be a little higher than the stovetop temp for a clean burn? I've never measured it so I am guessing here.

 

[cableman]

Idk lol i though i read it should go lower once stable! I need to get my wood sitchu set up better also and season more then a year!

 

[xman23]

what is this doghouse, lube and slide you speak of? *trying not to laugh too hard* I think I know what you mean by the slide-the air thingy? What is the doghouse and where might I find it? My air thingy does seem to stick a tad...or at least it doesn't seem to glide. Also there seems to be A LOT of play in the lever. Thanks

LOL, Thought we all knew Oslo slang. So your air thingy is sticky, it happens to all of us. Open the front door. See the dog house That thing with the three air holes in front. Remove the two bolts, look in there and you will see the slide that moves from the lever. Lube whole thing up "Dry Lube" get at HD. I find that lasts the longest.. Graphite works to. Lube the bolts and hand tighten. Never use the front door as somehow that makes the thing sticky, more often.

Also look for a mechanical bind with the lever.

When you get done it will so smooth.

 

[aaron1]

I noticed my rod is a bit tight as well sometimes when I slide it fully open. I hadn't thought I would need to lube it yet, as I've only used it for a few weeks. Maybe it gets slight obstructions sometimes?

 

[aaron1]

Holzwurm, If you find that type of blatantly sexual, low-level humor funny, I think that you need to learn a valuable moral lesson, such as that espoused by King of the Hill:

http://www.amazon.com/Thats-What-She-Said/dp/B00628E5H8

 

[vwmike]

I think one key point here, is the mention of kiln dried wood. I have the same experience when I burn a load of mill ends to get the house up to temp fast, once the secondaries start you can turn the stove down and they just take off like a rocket!

 

[aaron1]

That was my experience with the dry Elm as well. It went up really fast and I dropped the draft down really fast!