How to extend your stove's burn times

[woodchip]

I have not tried keeping my stove in all night yet, but I'm going to give it a try now just for interest.

I'll be loading with 3 splits of English Oak, and will post the results here. It's cold enough outside to encourage me to keep the stove alight, and as an experiment, it has to be worth 3 splits.

Even if it just saves a match

 

[begreen]

I am confused, there is a square hole in the back that lines up with the channel that goes up to the baffle, I was thinking this feeds the secondary air to the baffle, is this the case?

I bet there is. That is the way the 30-NC secondary manifold is fed.

Odd thing is that if the primary control is completely blocked, the fire is pretty effectively snuffed, secondary burn included. But my curiosity is piqued and I will be checking it out later.

 

[precaud]

I want to make it clear, I am NOT recommending that anyone alter the secondary air feed while the flames are alive. This is ONLY for after the flames die.

Though I must admit, I am seeing images of strategically-located bimetallic strips attached to secondary air flaps on some future experiment... Or maybe even timer-controlled. This process is crying out to be automated.

 

[Danno77]

This process is crying out to be automated.

100% agree with that.

 

[Shari]

OK Rox, I'll bite. Why do you live in a house where you have to dump heat into it while you sleep? What a waste of wood.

I guess every constructive thread has to tolerate its share of irrelevant posts. Sigh.

Well, I'm not Rox but the house I live in just happens to be located in a climate where outside temps can and do get down into single digits and below overnight. Frankly, I'm not willing to wake up to a cold house each morning. I do not consider it a waste of wood to heat my home over night. To each his own I would guess...

 

[woodchip]

I have just loaded my 3 splits onto the fire, will post pictures of the experiment in the morning.

I must admit, I do not think 3 splits is a waste of wood, I'm all for an interesting experiment.

How do I stop creeping down in the middle of the night to see how it's going......

That's the real test

 

[precaud]

This process is crying out to be automated.

100% agree with that.

Folks who HAVE to burn overnight could use it, then.

 

[NH_Wood]

I like the idea for increasing daytime burn times. I couldn't do this at night, because I load the stove about 45 min before bed and I won't be awake when the active flames turn to coals in order to close the secondary inlets. What I think I'll try is use some aluminum foil cubes that can 'plug' the secondary inlets after the coaling phase begins (during the day). I'll try a bunch of with and withouts and see if it seems to stretch the burn time out. I think it's great that folks tinker like this - always fun to read about, even if you never try it out. Cheers!

 

[oldspark]

Here is a post that talks about it.
https://www.hearth.com/talk/threads/66400/

 

[precaud]

Spark, if that's true, then the PE's would benefit some by this. But the reason they do so good stock is what I explained before: most of the secondary air comes out at the top front of the firebox and doesn't contact the bed of coals.

 

[woodchip]

So here are the three splits before I loaded last night, nothing special, probably quite small next to what some of you guys can get your stoves.

I dialled down the primary air on the airwash to about 10% after the flames had died down, and reduced the secondary air to about 20%.

I went to bed, and did wake up in the night, and crept down at 4am, just a glimmer there on the ash, and the flue pipe temp was showing 170c.

When I came down at 6-30am as usual, the fire looked as if it had gone out, but the flue pipe was showing 100c, and opening up the air just helped a few ashes to start glimmering.

Adding some kindling and a screwedup bit of paper it soon got going again, and I nipped back upstairs for a wash and shave.

By the time I was downstairs again, it was burning happily, and the usual pile of stuff got loaded!!

The lounge temperature was 72f this morning, outside was 33f, against yesterday 67f inside and 35f outside.
I think the experiment was worth 3 splits, but I only have 103 fully seasoned oak splits left, and to burn 3 splits a night for a month would leave me with just my birch and hawthorn plus some pallets. for daytime and evening use.

Must follow the example of others on here and work like mad to get 6 or 7 years ahead on the woodpile.

Night burning will then become the norm

 

[precaud]

Looks like it was a success, woodchip. Since you guys have multifuel stoves over there, the descriptors may be different. But if your 'secondary' air is the overfire air at the baffle, you can dial it down to nothing and just use the primary air to control the burn rate of the coals overnight.

 

[BrowningBAR]

OK Rox, I'll bite. Why do you live in a house where you have to dump heat into it while you sleep? What a waste of wood.

Because I don't want to live in a house that is cold when I wake up and have to spend several hours burning the cold out of 20" thick stone walls?

 

[oldspark]

OK Rox, I'll bite. Why do you live in a house where you have to dump heat into it while you sleep? What a waste of wood.

Because I don't want to live in a house that is cold when I wake up and have to spend several hours burning the cold out of 20" thick stone walls?

+1, its cool enough with out cutting the burn back any more, I do like the idea though for certain times of the year.

 

[Backwoods Savage]

When someone says they want longer burn times, that usually means they want enough red hot coals in the morning to do a "warm restart" without having to build a fire from scratch. Rake the coals forward, put in a fresh load of splits/rounds (maybe a couple sticks of kindling under them, maybe not), and in a few minutes, away it goes. Morning after morning, reliably. That is the goal.


Back to the comparison. Last night there was a movie on later than I usually stay up, which gave me a good excuse to do this. My normal procedure is:
1. Start the last load of the evening so that the flames will die out right around bed time.
2. When the flames die, close down the secondary air.
3. Close down the primary air ALMOST all the way. Go to bed.
4. Wake up in the morning, open the air controls, and within minutes have plenty of live coals for an easy warm start.

Interesting thread for sure but pardon my ignorance. First, my goal is a bit different from what you describe. I do not wish to wake up to only a small coal bed. I want to wake up to a warm house with the fire still going. Thank you.

I am also still trying to understand what you really do. You state that you wait until the flames die, close the air and then go to bed. Apparently you do not need heat in your house during the night?!

As for what we do, we load the stove just before going to bed. It takes at most 15 minutes to get the stove set and then we can go to bed and go to sleep. If I waited until the flames died, we would be sleeping in an icebox and that is definitely not my goal. Somehow, I still prefer warm over cold when I am inside my house. So I go to bed with the stove burning happily and wake up with it still burning happily. And yes, we also close the primary almost all the way.

Last night when I got up for the midnight run I also checked the stove. Stove top was just a tad shy of 600 degrees. House was very comfortable. This morning the stove top was at 375 and the house was still comfortable. I'm just about ready to add wood right now.

So, should I be concerned about plugging some air holes?

 

[Danno77]

Back Sav, I'm with you. At night I'm actually home where I can do something with the stove. Also, at night the temps outside are generally the coldest, meaning that I need to get more out of my stove. I don't have a stove with a secondary burn system, so this doesn't really apply to me, but I run my stove hottest at night.

Generally speaking i load up about 30-45 minutes before bed (I go to bed around 10:30), let it really get roaring and then cut it back to a spot that I know keeps the stove around 500-600 degrees. That means I won't make it through the night, but that's ok. I'm up to put the crying toddler back into bed, or because I have to go to the restroom. That usually happens between 1 and 3. At that point I throw a couple of the biggest splits I have in there and turn the air up almost all the way (I pack it a little better if it's 1 than if it's 3:00). Wake up at about 6:30 and pull the coals forward and make sure the air is on high to burn them down some. When I get there I fill it up and let it hit temps again and run out the door around 7:30-8:00.

Lot's of stove tending, but it's a small stove and I can be near it. If something happens and I can't get to the stove then i don't worry much, there are coals hiding in the ashes for long periods of time and the stove isn't my primary heat.

 

[jeff_t]

I think the experiment was worth 3 splits, but I only have 103 fully seasoned oak splits left, and to burn 3 splits a night for a month would leave me with just my birch and hawthorn plus some pallets. for daytime and evening use.

Must follow the example of others on here and work like mad to get 6 or 7 years ahead on the woodpile.

Night burning will then become the norm

Ya, you need more splits than you can count ;-)

 

[Battenkiller]

Precaud, I love how you think, but all I have to do is look at my stove to see it is custom made for a northern burner. The thermostat on my stove opens as the fire dies, not closes. This allows it to maintain stove temps throughout a time when most folks (except us guys with enlarged prostates) are sleeping and unable to adjust the inlet to allow more air in.

Maybe you can market the idea to our Florida burner(s)? JK... carry on.

Incidentally, you are a good and careful workman based on what I see in the photos. Now, invent a timer that rakes the coals toward the primary air inlet at 5:30 AM and I'm all over it.

 

[johnstra]

Wouldn't a flue damper work for those that have access?

 

[BrotherBart]

I want a stove that starts out at 250 degrees for four or five hours and then ramps up to six hundred for the second half of the burn. Our coldest temps all happen after two in the morning as the stove is cooling down. These stoves all work backward. >:-(

 

[Battenkiller]

I want a stove that starts out at 250 degrees for four or five hours and then ramps up to six hundred for the second half of the burn. Our coldest temps all happen after two in the morning as the stove is cooling down. These stoves all work backward. >:-(

Get up to pee and fill 'er up, old man. Or maybe your plumbing has aged more gracefully than mine has. %-P

 

[precaud]

Keep it coming precaud. I for one find it an interesting thread.

As do I, but it's being squashed by folks who aren't interested in it. Perhaps if they're done, we can get back to it.

First, my goal is a bit different from what you describe.

Doesn't matter, Dennis, the "goal" is not the purpose, it's just the setup for one way to apply it. It seems stupid that I have to say, if you have no need to extend the burntime of your stove, then you probably are not interested in this thread. Likely people who fall into this category would be:
folks who keep their stove stoked 24/7.
folks with cat stoves.
folks who are satisfied with their stove's burn time.
If I've missed someone, my apologies. The general idea is, if this topic doesn't appeal to you, we don't need to know about it.

The thermostat on my stove opens as the fire dies, not closes.

BK, the thermo on your stove controls the primary air, not the secondary air. It's been many years since I looked at the early Vigilant, but I don't recall it having a separate secondary air system.

Wouldn’t a flue damper work for those that have access?

I'm not fond of closing the exhaust and leaving intakes open. That's inviting a downdraft, and exhaust into your house. Better close/control the intake and leave the exhaust open.

I couldn’t do this at night... What I think I’ll try is ... during the day

Yep, it will work, day or night. You can use it as a floor polish AND a toothpaste! ;-)

 

[BrowningBAR]

Yep, it will work, day or night. You can use it as a floor polish AND a toothpaste! ;-)

Does it make Julienne Fries?

 

[precaud]

I still have the secondary air control I made for the Jotul F602, but I don't have the stove any more, so it probably wouldn't be helpful showing it to you. The secondary air inlet is at the bottom rear of the stove, behind the plate that has the label attached to it. To remove the plate, just drill out the rivets and use sheet metal screws to put it back in place.

The pics below show the air control I made for the Nestor Martin X33 secondary. Like the other air inlets, it is at the bottom of the stove, next to the ash pan. The control is just an aluminum shaft placed in a sleeve which is held in place by one of the ashpan screws, and has a plate on the end that covers the 1x3" secondary channel inlet. The shaft is then bent into shape so it clears both doors. Simple, and it works. The handle is small enough that a man riding by on horseback wouldn't notice it.

It's pretty easy to put these things together without having to make any permanent modifications to the stove. All the ones I've shown can be removed in a couple minutes and you would never know they were there.

 

[BrotherBart]

I want a stove that starts out at 250 degrees for four or five hours and then ramps up to six hundred for the second half of the burn. Our coldest temps all happen after two in the morning as the stove is cooling down. These stoves all work backward. >:-(

Get up to pee and fill 'er up, old man. Or maybe your plumbing has aged more gracefully than mine has. %-P

It must have. I ain't getting up when I can be sleeping. And no, I don't have plastic sheets either.