Wood Stove Firebox Size vs BTU

[abstovehunter]

Hey folks,

I came across this forum looking for answers to wood stove questions. There were lots of informative answers to another question posted, so I decided to join.

I am looking for a wood burning cookstove to use primarily as a heater, but have as a backup stove and oven as well. I am currently heating roughly 2400sf with a 30,000 BTU stove that is keeping up easily until -20. We often hit -40 for a couple weeks a winter, so I am looking for a significant BTU increase. I am limited by space requirements and have found a handful of stoves that will work, but I am confused as to how a smaller stove, the Vermont Bun Baker, with nearly the same size firebox can offer 65,000 BTU, while the Rosa XXl with way more thermal mass advertizes as 30,000 BTU.

As much as I would like a wood cook stove, I do not want to sacrifice heating capabilities for the occasional convenience. Can anyone explain how the same amount of fuel in the same size fire box can be produce such varied ratings?

Cheers!

 

[holeycow]

I am unsure how a 30,000 btu stove can heat 2400 square feet in Alberta. How big is that firebox?

my 2 cubic foot firebox keeps up to 1400 square feet easily until about -25, then has to be fed lots strategically when it gets colder than that. This is in a drafty old farmhouse...

oh, this stove is supposed to be 65,000 btu. I haven't a clue about that.

 

[Del_]

Wood cook stoves are a lot less efficient than wood heating stoves.

 

[abstovehunter]

The house is new and I am running a 35,000 BTU stove that was brought over from the last house to see how well it would work before buying the stove we want for this house. Firebox is 17” w x 12” h x 20” d. 2.3cf

The stove I intended to put in is rated at 30,000 and the firebox is 11.7" W x 12" H x 18.1" D. 1.47cf. I am now thinking this will be too small based on the performance of the above stove, so I am looking at other options.

The Bun Baker is rated at 65,000 BTU, but the firebox is 19" W x 13" H x 11" D. 1.5cf. There was a detailed review of it, the owner was heating a 2 story 2400 sq ft house. They cut a hole in the floor above the stove to circulate the heat and say it is working amazingly well. They did not, however, share their location. Arizona vs Alberta?

I understand that if the firebox is larger you can fit more fuel and BTU in it. I do not understand how you can get more BTU out of a smaller firebox, so my concern is that the stove I am running now has the largest firebox of them all and is running hard at -20. Could the 65,000 BTU's be accurate or will I find the company has just over rated it and it won't be big enough either? Or, is it possible the stove I really want (number B) which they claim is under rated at heating 1500sf, and can heat larger well insulated spaces (ie- my new house) might actually suffice.

Hoping someone smarter than me can shed some light on it.

 

[abstovehunter]

Wood cook stoves are a lot less efficient than wood heating stoves.

Granted. This is especially true for the larger, more elaborate style cookstove. I am looking at simple versions designed to be used as a heater with cookstove features integrated.

 

[Raintree]

You are most likely looking at a big difference in operating efficiency between the two stoves.

 

[Marine5068]

If you already have a cooking stove(electric or gas) then just get the largest heating woodstove you can and you'll be fine all winter. I's get an extra large stove like mine or even go to a Blazeking King.($$$)
Don't rely on manufacturers' claims, most over-advertise their specs.
Our temps easily get to -25 to -35 in Ontario and I use a Drolet HT2000 for main heat along with my Enviro Evolution pellet stove and both work fantastic.

 

[nathan4104]

I have an Elmira Fireview cook stove. Our house was built 9 years ago as electric heat so had a higher R requirement…. It’s a 1200sq ft bungalow……
The Elmira will ‘cook’ us out. It also won’t last the night with our high quality Poplar/pine.birch firewood. Not unless we jam it full, damper it down, damper down the chimney and maybe then in 8hrs there’ll be as much of a bed of coals as those woods leave. I’m sure good hardwood would be better but as in Alberta, this is what we got!
This firebox is 1.6cu/ft, takes 18-20” long pieces but they need to be split a bit smaller, which works better anyways.
We cook in the oven often, it’s perfect for Dutch oven pots of stew, roasts, etc as the oven is always 220-250 without doing anything special.
I had a water jacket in the firebox for a few years and pumped the water through my basement slab for infloor heat. We could keep the basement about 16-17°c up from 10-12°c with no heat at all. There wasn’t enough ‘power’ to do it properly, the water was too cold returning and so the jacket would be a big creosote ball in short time.
We burn 2-3 cords (real cords) and the electric forced air occasionally runs on the cold mornings if the fire went out through the night. Now with an electric on demand boiler doing the basement floor, our hydro bills are up about $100 per month during winter (overall with more furnace, lights, boiler and cloths dryer ran more) so I don’t think that’s too bad.
I hope you can find a decent cook stove for your house. We kinda built the house around ours and we enjoy it a lot.