Temps vs Box size

Most folks would much rather err on the large size than the small size and you'll have to look a long ways to find someone who complains because their stove is too large. However, some say that certain stoves are designed to be run with a full load of wood. I still find that difficult to believe but maybe it is true. But let's take this particular winter we are experiencing right now. Our Fireview is our only source of heat so we can not depend on a furnace for just a short fire or for one to come on during the night to keep the home up to temperature. Still, I estimate that as of today, we have run our stove with a full load of wood less than 10 nights and our heating season began in September. The stove still works just fine and we are comfortable in our house. I say if you like that particular stove, buy it, but regardless of the stove, make sure you have good dry wood and not marginal. It will pay great dividends. Good luck.

The bigger the stove the more mass ..therefore you would think more heat would be captured before going up the flue..If that's all true the bigger rock should transfer more of that heat to the living space.
I have been around small wood stoves that were really putting out some hot heat..almost crazy heat but yet 10 ft away it felt cool.
My stove does not feel that hot near it usually but the house is evenly warm...course it is a cat stove.
I would not have it any other way.

You can look at it a number of ways. Why pay for a huge stove if you're only loading 3 splits in it? If you have the cash then no problem. You may want to get overnight burns in a ~1000sqft house so you bought a 3cuft stove thinking bigger is better, load it up at night to get an 8hr burn and you are sweating your but off etc. Sure you can load that 3cuft stove less overnight and it wont cook you out nor will it burn overnight or you could load up a 1.8cuft stove and get the same result etc. And then there are are cat stoves which, big or small, can burn at more moderate temps over longer periods, Soapstone stoves that have a more even heat and maintain heat after being out, Cast Iron etc.

At the end of the day you have to live with it so buy what you like but there are things to consider with every stove and usually there is some compromise.

A bigger radiator means more heat is transferred if the surface temp is the same as a smaller one. It takes more wood to keep a bigger stove at the same surface temp as a smaller one for any given period of time. The minimum burn rate also climbs with firebox size. I like the big cat stove because it has the oomph to get it done in January but also burns low enough to not overheat the house in mild temps.

The three logs will NOT burn at the same temp in three different stoves. Each box volume is different, therefore volume of air to wood ratio will change, affecting draft strength of that particular set up. In a larger stove, it will take more wood to run the stove at optimum efficiency, with sustaining momentum. Three splits in a large box will lumber along at low temp, while that same volume of wood might get a small box cranking at higher temps.
In my opinion you should get a stove that is slightly bigger than what you need to heat, but not so big that you have to run it 1/4 throttle to stay comfortable. A stove at 350 is too cool. You should burn 400-600 range to burn cleanly and safely. That being said, a large box at that temp may leave you opening up windows to cool off. It all depends on your house size.

Again in my opinion, get the stove that will enable you to heat your whole house without using fossil fuels!

CRC said:

The three logs will NOT burn at the same temp in three different stoves. Each box volume is different, therefore volume of air to wood ratio will change, affecting draft strength of that particular set up. In a larger stove, it will take more wood to run the stove at optimum efficiency, with sustaining momentum. Three splits in a large box will lumber along at low temp, while that same volume of wood might get a small box cranking at higher temps.
In my opinion you should get a stove that is slightly bigger than what you need to heat, but not so big that you have to run it 1/4 throttle to stay comfortable. A stove at 350 is too cool. You should burn 400-600 range to burn cleanly and safely. That being said, a large box at that temp may leave you opening up windows to cool off. It all depends on your house size.

Again in my opinion, get the stove that will enable you to heat your whole house without using fossil fuels!

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Good post.
If I want to just burn a few splits in mine I really have to open it up to get some good heat..I rarely do that..but I have.
But like you say..in a small stove those same few splits will heat er up faster and hotter with less air.

But you would need less air flow in a smaller stove to burn the same wood..the air is not static.
Less air in..less air out...less heat up the pipes ..maybe?

I dunno.
BK recommends full loads and that makes sense to me.
If you do half loads you have to waste fire just getting the stove and cat back up to temps twice as much.
Being a cat it's a very controllable stove ..so full loads not a worry.

I just have a hunch that smaller stoves may be more efficient ..cat or tube..but I don't know for sure.
That said..to much fire in a small stove and the stack temps will increase considerable..which would be heat up the pipes again.

Nothing burns well in a Burger King. Chimney is too short.

Can't you always add a few fire bricks to a larger stove in shoulder seasons to reduce "firebox size" and still have the room to pack it up in the cold snaps? (I seem to remember this somewhere on here being mentioned a few times just couldn't find the posts I wanted to reference)

Please correct me if I am wrong about this!!

I think one of your basic assumptions is wrong- you can't have the same small fire in a bix stove that you could in a small stove. A small load of wood in a big box doesn't burn as well as the same load of wood would in a smaller box. A fire requires air and heat, and heat is controlled by the surroundings of the fire. Look at a campfire or even the fire in your woodstove. The part of the wood that burns isn't the top of the wood, where air is most available. The part that burns is the part of each log resting on coals or facing against other wood. As one log burns some of the heat is reflected back by the other adjacent log and this helps maintain the high temperature needed for combustion, or both adjacent logs burn and heat each other. If you spread the logs out they will smoulder or stop burning. In a stove with a full load the insulated sides of the stove firebox help hold in heat and allow the wood to burn better. Take that same load of wood and put it in a larger stove and the sides of the stove would be farther away and therefore a little less effective at keeping heat on the fire, so the fire would burn differently. Move the same load of wood onto the driveway and it might stop burning. You will have hotter, cleaner fires when the size of the stove is about right for the size of the fire you are building. There is some leeway, of course, so you can make a slightly larger or smaller fire to suit the situation, but I wouldn't want to deliberate have a situation in which I was always building a small fire in my big woodstove; the stove simply wouldn't work quite as well as it should.

Maybe with a cat stove a small smouldering fire is fine since the cat can help maintain a clean burn at lower burn rate.

krysssyann said:

Can't you always add a few fire bricks to a larger stove in shoulder seasons to reduce "firebox size" and still have the room to pack it up in the cold snaps? (I seem to remember this somewhere on here being mentioned a few times just couldn't find the posts I wanted to reference)

Please correct me if I am wrong about this!!

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You can, and while it will reduce the firebox size, it will increase the mass to be heated, while not decreasing the radiant surface. Should still help some, nonetheless.

Thanks Dune, thats what I was thinking, was not a perfect solution but may just help just a smidge in shoulder seasons

neumsky said:

...which stoves have to run with a full load?

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Downdraft stoves like mine need a hot, intense fire to get a good secondary burn in the back chamber. If you have a small fire in a large box, the intensity of the fire is not concentrated enough with all the extra airspace, and the afterburner can stall out. With a full load, the secondaries always kick in and last a good long while without any need to fiddle with the air control and/or bypass damper.

krysssyann said:

Can't you always add a few fire bricks to a larger stove in shoulder seasons to reduce "firebox size" and still have the room to pack it up in the cold snaps? (I seem to remember this somewhere on here being mentioned a few times just couldn't find the posts I wanted to reference)

Please correct me if I am wrong about this!!

Click to expand...

Yes, I'm one of the guys that did that and posted about it. The smaller firebox (by adding brick) allowed me to build a smaller fire and get a quicker-starting and longer-lasting secondary burn without cooking myself out of the house.

thanks for the good ideas about stretching a bigger box in shoulder season. it will be my first year next year with two stoves and the Napoleon will be a decent sized stove but it will be heating a good sized 1000 sq feet in the basement (will be adding insulation this summer as we finish it) and working on helping make the upstairs toasty in conjunction with the Venice in the fireplace. I figured each stove didn't need to be packed to the gills, but I found the Venice can't totally keep up with frigid temps and we needed heat for the basement so I convinced hub for a second stove, and a brand-new from dealer Napoleon 1900p (with webbed arch door) for $1050 was just to good to pass up

branchburner said:

krysssyann said:

Can't you always add a few fire bricks to a larger stove in shoulder seasons to reduce "firebox size" and still have the room to pack it up in the cold snaps? (I seem to remember this somewhere on here being mentioned a few times just couldn't find the posts I wanted to reference)

Please correct me if I am wrong about this!!

Click to expand...

Yes, I'm one of the guys that did that and posted about it. The smaller firebox (by adding brick) allowed me to build a smaller fire and get a quicker-starting and longer-lasting secondary burn without cooking myself out of the house.

Click to expand...

Are you saying that you added more firebrick to reduce the overall size / better insulate your firebox??

Interesting........

@ branch, i am trying to go through your old posts now to see where you referenced it, I wanted to ask when you did it if you recommend (or have any opinion) on the "type" of firebrick to add for this, a more pumice one or a heavier one? or if you did any compares/have any opnions/insights to what to try

DUNE you and I are on the same page with this concept. Another thing to consider regarding small or large fires....if you see smoke out your stack your fire is too small and too cool. (I'm sure I'm not breaking any news here), but my point is for the sake of wood stoves, they are meant to keep us warm and help us survive essentially. Is is not a bit pretentious to think we can get by with a small fire today because we feel like it? If you were a caveman you'd be dinner. Just get the thing hot and big and then tweak it from there and keep your damn house warm and your wife happy!

Sorry if I veered off topic. Good luck with finding the right stove everybody. And in reality, any stove vs. no stove IS the right stove....