Discussion: hotter fire or slow burn?

[bholler]

View attachment 310396

Simple air controls work well with no maintenance for many many years. Some have had more complicated air controls and they usually end up being a maintenance problem down the road

 

[Prometeo]

Non cat stoves (atleast the ones we have in the states) absolutely do not burn most efficiently with the air all the way open. Doing that wastes a large percentage of heat out the chimney.

I believe that air all the way open,
does not mean too much air. What decides air is draught, and the draft is always proportionate to the heat, a quantity of wood that is burning. Yes, cat stoves it is opposite, better in slow burning but always efficient

 

[Prometeo]

My jotul f400 kicks out much more heat when there are robust secondary flames. When choked down enough, the secondairies are either weak or off. And with that the stove is much cooler. I don't find the splits last that much longer when the stove is overly choked down, but i do find the heating is much deminished. Unburnt fuel is a waste. I'd rather err on the side of letting to much heat escape the chimney than let cool unburnt fuel out of it.

I have come to the same conclusion also confirmed by thermometers

 

[VirginiaIron]

Hi all…

I saw a video recently online with a guy who suggested running your stoves hotter throughout the day in order to have a more stable temperature environment, and for me, more importantly, to use less wood.

This kind of struck me as being counterintuitive, since I have always thought that if I get my stove burning as low as I can (that would be practical), I would go through wood less quickly…

His experience has been that when he burns hotter, it heats the house up more robustly, and it takes a longer time for the house to cool off, therefore he has to have fewer fires during the day… By contrast, my fires result in a cooler house with more dynamic temperature changes, from what it seems.

What have your experiences told you about this?

I am trying it now, but yet to have any new enlightenment.

Depends on the stove, home, and outside temperature. We've learned how to adjust our burning for our needs. Most times we get a good fire going and then throw just two or three pieces in to maintain comfortable temperatures inside- that saves us wood. Now if we're looking for the nap inducing 80 plus degrees, the stove gets fully stoked.

 

[Defiant 3]

With regard to the O. P. 's difficulty controlling the stove's heat output, wouldn't an old fashioned cast stovepipe damper be helpful? They appear to be making a comeback of sorts, especially on 2020 compliant stoves.

 

[bholler]

I believe that air all the way open,
does not mean too much air. What decides air is draught, and the draft is always proportionate to the heat, a quantity of wood that is burning. Yes, cat stoves it is opposite, better in slow burning but always efficient

You can believe what ever you want. But it doesn't change the fact that secondary combustion stoves don't run most efficiently wide open. In fact most will be over fired and destroyed by doing that.

Now yes depending on the stove, fuel, chimney, weather conditions etc etc the ammount you shut back will vary. But running wide open is not the right way unless you have insufficient draft

 

[Prometeo]

You can believe what ever you want. But it doesn't change the fact that secondary combustion stoves don't run most efficiently wide open. In fact most will be over fired and destroyed by doing that.

Now yes depending on the stove, fuel, chimney, weather conditions etc etc the ammount you shut back will vary. But running wide open is not the right way unless you have insufficient draft

I like to reduce air, and initially it seems beautiful, the fire, slow, because the flue has a heat latency, but then this drops in temperature, and fire loses a lot, but certainly impossible to generalize. When there is wind for example, I close the damper because in that case, it is clear too much air, not good

 

[bholler]

I like to reduce air, and initially it seems beautiful, the fire, slow, because the flue has a heat latency, but then this drops in temperature, and fire loses a lot, but certainly impossible to generalize. When there is wind for example, I close the damper because in that case, it is clear too much air, not good

To me that sounds like weak draft or wet wood

 

[bigealta]

I like to reduce air, and initially it seems beautiful, the fire, slow, because the flue has a heat latency, but then this drops in temperature, and fire loses a lot, but certainly impossible to generalize. When there is wind for example, I close the damper because in that case, it is clear too much air, not good

Yes my jotul f400 can do the same thing. Is a matter of how quickly u turn the draft down and how far you close it. I find when going past 1/2 way closed, especially early into the burn, the f400 can get very touchy.

And draft and wood moisture also play a large role in this behavior. You can tell the difference when you burn very well seasoned wood.

 

[Prometeo]

Yes, some of my woods are 22 percent, elms, while oak, 10 moisture. I notice a large draft, and possibility to reduce when I have some thin wooden boxes, and carpentry boards, which is soft wood, it seems that I can play with the air without particular problems, but with oak, elm, not small pieces I can not close, if I do I notice a little smoke from the chimney which I normally only see when lighting the fire. Surely also the flue, which is single wall, loses a lot of temperature and therefore draught, but still I'm feeling pretty good so far. I don't know if this can be considered too much draft

 

[bholler]

Yes, some of my woods are 22 percent, elms, while oak, 10 moisture. I notice a large draft, and possibility to reduce when I have some thin wooden boxes, and carpentry boards, which is soft wood, it seems that I can play with the air without particular problems, but with oak, elm, not small pieces I can not close, if I do I notice a little smoke from the chimney which I normally only see when lighting the fire. Surely also the flue, which is single wall, loses a lot of temperature and therefore draught, but still I'm feeling pretty good so far. I don't know if this can be considered too much draft

Nothing about your description indicates to much draft if anything to little draft

 

[bigealta]

Definitely not to much draft in that video clip. I'd say pretty good, looks like the secondaries are winding down and fire is moving toward coaling. All good I'd say.

 

[Prometeo]

beginning of February I had done this, note air half closed, but inside I had only soft wood

 

[bigealta]

beginning of February I had done this, note air half closed, but inside I had only soft wood

I still would not call that too much draft. Probably pretty good burn rate. Could close it a bit more to see if you can get just mostly secondary burn on top. But it will be touchy as you close it down. That said i can at times run a good burn with the draft closed most of the way. But that's with super dry hard wood or fully packed softwood. And i don't have a very strong draft with only about 16ft chimney.

 

[Prometeo]

I still would not call that too much draft. Probably pretty good burn rate. Could close it a bit more to see if you can get just mostly secondary burn on top. But it will be touchy as you close it down. That said i can at times run a good burn with the draft closed most of the way. But that's with super dry hard wood or fully packed softwood. And i don't have a very strong draft with only about 16ft chimney.

The air sensitivity of these stoves is due to the rapid transfer of heat, I applied a brick floor and a kind of airmate, and now yes, I can close the air but the stove continues to draw, probably because it keeps warmer, and also the chimney, hotter, perhaps efficiency is a little less, Perhaps.