Fire Box Capacity Unreliable Measure?

[Mass. Wine Guy]

I spoke with the president of Jotul USA the other day about the fire box capacity of the F3 CB Jotul wood stove. He told me there was no standardized method to measure this, which is why Jotul does not put this information in its product information. Then he said Jotul prefers to list how many "average" size logs each stove can fit. This seems even less standardized to me. The Quadrafire Yosemite stove is listed as having a fire box with 1.45 cubic feet capacity.

Can someone please put this in context fr me? Is 1.45 cubic feet a lot, miniscule?

Thank you.

 

[Corie]

No standardized way? Hrmmmmmm, that's a fishy comment. There is a way to measure the firebox capacity and it is defined in the testing codes SINCE the firebox volume is use to properly size the test load.


1.45 is on the small side of fireboxes, certainly on the cusp of not being an overnight burner. If you'd like the EPA definition of firebox volume, I'd be happy to post it directly from method 28 or you can check it yourself on the EPA website. You're looking for EPA test Method 28, it will be listed in there.

 

[Highbeam]

I would clssify 1.45 CF as miniscule. In Massachusetts it is very miniscule. My last firebox was over 3 CF, this one is about 2.3 and considered medium. I wouldn't want any smaller.

 

[jpl1nh]

Certainly you can take the fire box dimensions and multiply them together then divide by 1728 which is the number of cubic inches in a cubic foot. For example, my Keystone has a fire box size of 13 x 11 x 18 which is 2574 cubic inches divided by 1728 = 1.49' sq firebox, definately a small box. It might actually be 1.51 or 1.47 cause there are some nooks and crannies. Bottom line is it's not a 3 cubic foot fire box. Yes a 1 and 1/2 cubic foot fire box is on the small side. Because my stove is a cat and a soapstone stove, I get away with a bit longer "burn" times than other small stoves but it's still small.

 

[jpl1nh]

If you’d like the EPA definition of firebox volume, I’d be happy to post it directly from method 28 or you can check it yourself on the EPA website. You’re looking for EPA test Method 28, it will be listed in there.

Hmmm.. Corrie, I checked out method 28 and it seems a bit, shall we say, ambiguous? Still, a 1.45 cubic foot firebox is much smaller than a 2.5 or a 3 cubic foot box. Seems kind of like splitting hares (sorry Bugs)

 

[Mass. Wine Guy]

Thanks. This will help when I take a tape measure with me to the stove shops.

Certainly you can take the fire box dimensions and multiply them together then divide by 1728 which is the number of cubic inches in a cubic foot.

 

[BrotherBart]

Thanks. This will help when I take a tape measure with me to the stove shops.

Certainly you can take the fire box dimensions and multiply them together then divide by 1728 which is the number of cubic inches in a cubic foot.

Remember that they count every square inch. Including the space under the baffle that they say to not stack wood in. That space is needed for a secondary combustion chamber.

 

[begreen]

I found it pretty straight forward to measure the Castine's firebox. This sounds like blowing smoke to me. 1.45 cu ft is a small firebox, but not minuscule. It all depends on what one needs for heat and what will fit. The Castine or Yosemite can do a 6 hr burn on softwood. Both will have coals after 8 hrs. for restarting. Cranked up and running at 650-700F, both stoves put out a lot of heat.

 

[webbie]

He is right that there is no standard in terms of REALLY meaning how many pounds of wood you can fit in compared to another unit. Yes, you can measure the cubic inches or feet, but only taking a pile of logs and loading it up (cold) can give you a comparison with another stove.

Read this for a rough idea of sizes and their applications:
https://www.hearth.com/econtent/index.php/wiki/Choosing_a_Wood_Stove/

 

[JimWalshin845]

He is right that there is no standard in terms of REALLY meaning how many pounds of wood you can fit in compared to another unit. Yes, you can measure the cubic inches or feet, but only taking a pile of logs and loading it up (cold) can give you a comparison with another stove.

Read this for a rough idea of sizes and their applications:
https://www.hearth.com/econtent/index.php/wiki/Choosing_a_Wood_Stove/

This really strikes a cord. We are avid kayakers. Yep, those tiny boats that go down white water, lakes, creeks, bays and even ocean swells 3'-4' high. Stability and volumn are areas that are often discussed. We own about a dozen kayaks on any given day and they range in all different sizes.

There is no reason why a manufacturer CANNOT give you the EXACT dimensions on the stove. How you stock it full of wood is another topic but strict dimensions are readily available to the factory. It may vary in milimeters, but if it varies more than that then the product is not worth considering.

I have seen BTU ratings by some manufacturers that really need a education in thermodynamics too. If a President of a Corp tells you that HE/SHE can't give you a DEFINITIVE answer as per size/dimesion of their product, you really have to scatch your head as per why they are in business and why their product should be considered as a GOOD consumabale product?

I wonder why more manufacturers (or their direct staff) are not here on the forums? Yes, there are a few and they show a true concern for the end user and I imagine learn alot of what the end consumer desires. Those manufactures and their staff deserve Koodoos!

I believe the people here who post regularly are the heartbeat of wood stove afficianados who compliment all sorts of desires, environments and social strata. Why shouldn't the manufacturers listen to US? :question:

Off my firebox,
Jim

 

[Corie]

Yes, these firebox dimensions which you all desire are CAREFULLY and strictly maintained and recording during the manufacturing process.

 

[babalu87]

I spoke with the president of Jotul USA the other day about the fire box capacity of the F3 CB Jotul wood stove. He told me there was no standardized method to measure this, which is why Jotul does not put this information in its product information.

ROFL
Either he is HIGHLY uninformed or they just dont know how to use a tape measure.

 

[synthnut]

I think that the manufacturers basically tell you what you want to hear ....I'm not sure where they get their btu ratings from , but that's sure one measurement that most companies are WAY off base on .... I've come to find that when searching for that perfect fire box , that when you see them in person , some of them are even more impressive, but most are a lot smaller than you envisioned in the product catalog .... and there are those select few that really tell it like it is no blowing smoke !!.... This is one reason why this forum is such a blessing ....Real people using the products from all around the country ....NOTHING beats real life experiences no matter what the numbers say !!..... Jim

 

[Corie]

Directly from Method 28:


Firebox Height: Means the vertical distance extending above the loading door, if fuel could reasonably occupy that space, but not more than 2 inches about the top height of the loading door, to the floor of the firebox. Firebox height is not necessary uniform and must account for variations caused by internal baffles, air channels or other permanent obstructions. (I.E. If the secondary tubes are 4 or more inches apart, the firebox height is to the bottom of the baffle; if they are closer than 4 inches, the firebox height is to the bottom of the tubes).

Firebox Length: Means the longest horizontal fire chamber dimension that is parallel to a wall of the chamber.

Firebox Width: Means the shortest horizontal fire chamber dimension that is parallel to a wall of the chamber.



Firebox Volume: Determine the firebox volume using the definitions for height, width and length above. Volume adjustments due to presence of firebrick or other permanent fixtures may be necessary. If a firebrick occupies less than 1/3 the total height of the firebox side it is on, you must account for the extra space above it.

If the area above an ash lip is less than 10% of the total firebox volume, you can exclude it. However, north-south burners often count this volume, since consumers will often load wood onto the lip.


I can clarify anything that might need explanation. I'm not sure with is vague or difficult about this, honestly? We're required to calculate it and follow it to a tee, and Jotul is doing the same thing when they emissions test their stoves.

 

[Mass. Wine Guy]

Well, according to my very rudimentary measurements of the Jotul Castine, it seems to have a fire box of about 1.45, maybe 1.5 cubic feet. Anything larger in the Jotul line would be too much heat (as well as money) for me. Any particular problems or issues known about the Castine? Thanks very much.

 

[jbrown56]

Hi, I just got my stove about five weeks ago after using the same stove for 26 years and heat 2100 sq. ft. 24/7. The decision for me was somewhat simplified because I had to try to match the size of the firebox to what I already had. When I started looking the fireboxes looked somewhat smaller than I had. I think it is because of the unusable space I could see in the top of the old stove. Anyway, I'm happy with the stove I got and it heats the house better than the old stove.

Jim

 

[Mass. Wine Guy]

Thanks, Chuck. What new stove did you get?

 

[Mike Wilson]

FWIW, Cast and I measured up our Kennebecs. We came up with about 2.2 or so.

-- Mike