I generally agree there isn't a huge difference, but in my experience there is a definite perceivable difference. If you compare a stone stove at 600 degrees vs a steel stove at 600 degrees, I agree there won't be much difference. But to be fair, you should compare a stone stove at 600 degrees (around maximum temp) to a steel stove at 700 or 750 (around maximum temp). I absolutely notice a difference when you compare it that way. Also, there is certainly a flatter heating curve with a stone stove. No question.
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I generally agree there isn't a huge difference, but in my experience there is a definite perceivable difference. If you compare a stone stove at 600 degrees vs a steel stove at 600 degrees, I agree there won't be much difference. But to be fair, you should compare a stone stove at 600 degrees (around maximum temp) to a steel stove at 700 or 750 (around maximum temp). I absolutely notice a difference when you compare it that way. Also, there is certainly a flatter heating curve with a stone stove. No question.
jharkin
Minister of Fire
I foresee this turning into one of the annual "does a blower increase efficiency" threads that go on for 20 pages but never get resolved......
BrowningBAR
Minister of Fire
You can absolutely run a Fireview hotter than 600. Why compare max temps? We are comparing two stoves running at the same temp.
I have consistently found otherwise.
I get the steel stove up to temp, it hovers there for several hours, and then slowly begins to come down.
I get the cast iron stove up to temp, it hovers there for several hours, and then slowly begins to come down.
I get the soapstone stove up to temp, it hovers there for several hours, and then slowly begins to come down.
All three stoves will hover around 300 degrees for quite some time during the end of the burn cycle. The Soapstone stove will hold onto heat a little longer in the end, but it is not worth making that a deciding factor for your purchase.
I have nothing against soapstone and I will probably own one (or three more) in the future. But soapstone is not the reason why I would buy the stove. All three materials are great for heating your home. But, the difference between the three stoves is more cosmetic than it is results oriented as it regards heating your home. Are there differences? Yes. Is the differences huge factors? No.
Any quoted BTU/hr rating is a power output claim just by nature of the units. I think you know this BB. But for others trying to understand this... Energy(BTU) over time (hr) equals powe... time rate of change of energy output. I added the term instantaneous to emphasis that power is an real time value.
MnDave
I foresee it ending up in the Inglenook pretty soon where discussions belong. So somebody looking for real information doesn't end up wading through a few hundred posts finding nothing but conjecture.
I have 3 degrees in Mechanical Engineering with an emphasis on Thermodynamics & Heat Transfer, and I can't figure out for the life of me what the hell the point is here. 
I am not implying anything. I am presenting numbers for intelligent discussion.
Maybe (repeat maybe) since cast iron is not homgenous due to the porosity (tiny gas pockets) the speed at which the initial heat wave moves through the material is slower than in homogenous steel.
Really BB, I am just looking for a way to explain all the things we see with stoves and how they perform.
MnDave
I have 3 degrees in Mechanical Engineering with an emphasis on Thermodynamics & Heat Transfer, and I can't figure out for the life of me what the hell the point is here.
Read the title of the thread.
MnDave
I suspect it's the firebrick insulating the firebox and lower thermal mass. Thermal conductivity is just a part of the overall picture. It is an indication of how quickly the heat will transfer from the fire to the outside of the stove. If you want a strongly radiant stove then cast is a good way to go. But in some applications one does not want an intensely radiant stove. The most typical being an installation where clearances are important. Another property that is desirable in a stove is thermal mass. By this I mean the ability to store heat, then release it over time. Soapstone is an excellent material for thermal storage. When used in a stove it provides a very desirable soft heat instead of an intense blast. When the fire had died down, the stove continues to gently release this heat for hours. You will also see hybrids which have an inner, steel stove jacketed in cast iron. This has a similar effect in that it takes advantage of the thermal mass of the cast iron to soak up, then slowly release the intense radiant heat from the inner steel stove. These stoves have a characteristic similar to soapstone stove's soft heat.
There really is no best material. It's the best material for the job at hand. If you only want the fastest heat transference from the fire, then the thin 24ga steel of a glowing red Ashley Columbian or a barrel stove should be in your house, with lots of room around it.
(No eng degree here so apologies in advance to Rick and others that can provide better terminology or descriptions.)
BrowningBAR
Minister of Fire
And I am relating actual experience with all three materials and how there is little difference between the three.
FanMan
Feeling the Heat
You are comparing different units.
1 BTU/hr - ft= 12 BTU - inch/hr -sf -
I will admit to not using an exhaustive seach on the thermal conductivity values I used but in all cases that I found, cast was higher than steel.
MnDave
No, I used the units I found quoted, same for both materials, then converted into the units used in the first post.
Those were the numbers I found on several websites; there were minor variations in the figures given but they were pretty close.
BrowningBAR
Minister of Fire
And the term "instantaneous" is what makes it a false statement on your end. Pellet, coal, wood. None of them offer "instantaneous" heat.
Do not take my posts as me angrily disagreeing with you. I am simply highlighting areas of your comments and responding.
Oh, I've read it. Didn't find it very enlightening. Other than leaving little burn scars on our arms, heat transfer by conduction has little or nothing to do with the performance of a wood stove. Rick
If you fellows wouldn't mind, I would like to slide one more variable into the equation. If you would like to disregard it,i won't be offended. Residency time of the heated gasses affects heat transfer as well. Less heat being transferred through the stove body means hotter firebox. A hotter firebox means you can further close your damper further. Lower damper setting means gasses move slower. Slower moving gasses means longer residency time. Longer residency time means more heat transfer. This is why stoves of every different build type perform similarly. Different characteristics to each one, but ultimately similar.
That tulikivi site is where I got my thermal conductivity value from.
I then used this site for the conversion.
http://www.engineeringtoolbox.com/thermal-conductivity-calculator-d_857.html
BTW here is what the tulikivi site says about thermal conductivity.
Thermal conductivity
The fact that soapstone has a better thermal conductivity compared to other materials is a consequence of its dense structure and mineral composition. This characteristic enables balanced and rapid warming throughout the soapstone structure.
I just do not get it. And this is the reason for me starting this thread. Something is not right. Maybe the "other materials" they are comparing soapstone to are not cast iron and steel as tulikivi is known for their enormous "heat accumulating fireplaces" and not stoves as far as I know.
MnDave
Could that be a different thread?
I was hoping to stay on the subject of the base materials for awhile so that we can have a reference for further dicussion.
MnDave
I respect that you are a moderator but why do you need to taint this thread with your personal opinion.
Other mods have scolded me for taking a thread off track so I started my own. If you do not what to comment here then .... you know ....
MnDave
Sincerely, I have been puzzled about soapstone stoves long before I came to this forum.
I am not a stove saleman so I have no axe to grind with anyone. I simply want to understand what I am reading.
I have requested a demo on a soapstone stove. The dealer has yet to contact me.
I stood next to a small soapstone stove a few years ago. The fire was almost out. The stove was still warmish. The salemans said that I would not be interested in that because the "heat is too gentle". That has been my only exposure the soapstone excwpt for cold stoves in the showroom.
You know guys, if the mods here are just going to swoop down on me everytime I start a controversial discussion, I won't stick around. If that makes anyone here happy then I assume that they are a stove salesman here pandering their wares.
MnDave
"Assume" anything you want. But this is not a venue for controversial discussions of any kind.
webbie
Seasoned Moderator
One would have to do a myriad of calculations on all this stuff to come up with any Best Guesses, but these are probably not findable on a simple google search. As an example, certain wavelengths of radiant energy pass right though materials! These are barely affected by the slight differences in some materials (cast/steel).
It is NOT true that a steel surface at 600 degrees puts out the same heat as one of cast of one of steel or one of tile, etc.......each may be VERY different depending on the internal stove design and how radiant energy is forced outwards through the parts of the stove.
An example I always used is the Resolute Acclaim, which is intentionally insulated on most all parts of the stove- which obviously hampers radiation greatly through a number of sq ft of the surface. The heat is forced to emit mostly through the top plate and the rear and it comes through as a HEAVY radiation, so much so that wood mantels need to be especially far above it! If it were true that one heated surface of x sq ft was the same as another, this wouldn't make sense.
To summarize, there are a lot of things which affect stove design. Colder materials (cast/steel) may radiate quicker from a cold start, but they also quench the fire inside the stove resulting in other problems.
I can't speak for HearthStone since I haven't spent time inside their lab, but I do know that the Progress was many years in design and the team who put it together has been in this business since the early days of Vermont Castings. It was tested with the same EPA standards as the others and was turned to work BOTH for those standards and for the hardwoods and other stuff real woodburners use...
I've never claimed one stove is the "best", but other than OWB's and some other questionable ad claims, I think you will find that the top brands of stove do a relatively honest testing...add user experiences to those, throw in a dose of common sense, and that should do the trick....
BTW, many years ago the top wood heat researched put together a theoretical design for what an efficient wood stove might look like (they didn't exist back then). You'd find the design quite similar to a modern soapstone stove in terms of it's heavy use of refractory to keep the inside temps hot and the fire from quenching.
It is NOT true that a steel surface at 600 degrees puts out the same heat as one of cast of one of steel or one of tile, etc.......each may be VERY different depending on the internal stove design and how radiant energy is forced outwards through the parts of the stove.
An example I always used is the Resolute Acclaim, which is intentionally insulated on most all parts of the stove- which obviously hampers radiation greatly through a number of sq ft of the surface. The heat is forced to emit mostly through the top plate and the rear and it comes through as a HEAVY radiation, so much so that wood mantels need to be especially far above it! If it were true that one heated surface of x sq ft was the same as another, this wouldn't make sense.
To summarize, there are a lot of things which affect stove design. Colder materials (cast/steel) may radiate quicker from a cold start, but they also quench the fire inside the stove resulting in other problems.
I can't speak for HearthStone since I haven't spent time inside their lab, but I do know that the Progress was many years in design and the team who put it together has been in this business since the early days of Vermont Castings. It was tested with the same EPA standards as the others and was turned to work BOTH for those standards and for the hardwoods and other stuff real woodburners use...
I've never claimed one stove is the "best", but other than OWB's and some other questionable ad claims, I think you will find that the top brands of stove do a relatively honest testing...add user experiences to those, throw in a dose of common sense, and that should do the trick....
BTW, many years ago the top wood heat researched put together a theoretical design for what an efficient wood stove might look like (they didn't exist back then). You'd find the design quite similar to a modern soapstone stove in terms of it's heavy use of refractory to keep the inside temps hot and the fire from quenching.
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