soapstone

[rmcfall]

My understanding has been that soapstone provides more of a gentle heat compared to cast iron. Recently, however, I read a post that said people were blasted out of a room because of the heat from a soapstone stove. Is there really a noticeable difference between the heat that is felt from soapstone vs. cast iron? Or is the main advantage to soapstone the retention qualities of the stone itself?

Also, in terms of spreading heat into other rooms, are soapstone and cast-iron equivalent, with only a convection stove or insert doing a better job?

 

[Todd]

This is my take on soapstone.

I think soapstone has a more even heat because of the mass and heat storage properties of soapstone. When you fire up a soapstone stove it takes a little longer to bring up to temp, but stays at a constant temp longer, and seems to hold heat a few hours longer.

When you fire up a steel stove you get a fast searing heat, then the heat subsides at a faster rate than a soapstone stove. Steel and cast iron do get hotter, but I don't know if they transfer more heat than soapstone. The efficiency numbers are the same.

Both stoves have their advantages and disadvantages, and will blast you out of a room if its a small room. It's best to have a open floor plan and locate your stove in a centrally located area of your home.

As far as convection vs radiant, all stoves do both. Don't get caught up in that debate. Inserts are called convection stoves because they are placed inside a fireplace and need convection chambers to circulate the air around the stove and back out into the room instead of being absorbed by the fireplace.

I have had 3 steel stoves and 1 soapstone stove, and I personally like the soapstone better.

 

[rmcfall]

Thanks for the feedback, Todd. So it sounds like once a soapstone stove achieves the desired temperature, it is easy to maintain such a temperature without the peaks and valleys like a cast iron or steel stove. The soapstone seems like a good choice as long as the fires are kept going all the time. How many square feet are you able to heat with your Homestead?

I was curioius about the convection and radiant differences--partly from reading on this site, as well as seeing stoves that are advertised as convection. Morso advertises some of their stoves as convection, and my prior stove (Waterford Ashling) was also advertised as convection so I've never had anything else with which to compare.

This is my take on soapstone.

I think soapstone has a more even heat because of the mass and heat storage properties of soapstone. When you fire up a soapstone stove it takes a little longer to bring up to temp, but stays at a constant temp longer, and seems to hold heat a few hours longer.

When you fire up a steel stove you get a fast searing heat, then the heat subsides at a faster rate than a soapstone stove. Steel and cast iron do get hotter, but I don't know if they transfer more heat than soapstone. The efficiency numbers are the same.

Both stoves have their advantages and disadvantages, and will blast you out of a room if its a small room. It's best to have a open floor plan and locate your stove in a centrally located area of your home.

As far as convection vs radiant, all stoves do both. Don't get caught up in that debate. Inserts are called convection stoves because they are placed inside a fireplace and need convection chambers to circulate the air around the stove and back out into the room instead of being absorbed by the fireplace.

I have had 3 steel stoves and 1 soapstone stove, and I personally like the soapstone better.

 

[Bushfire]

Our Morso 3450 has soapstone sides and feet which hold the heat for a good 4-5 hours after the fire has substantially subsided. It does take a while to get going, but it also does not push us out of the room, which is a finsihed basement, area about 600 square feet.

 

[rmcfall]

How much does the heat from the soapstone heat the room for those 4-5 hours when the fire has subsided?

Our Morso 3450 has soapstone sides and feet which hold the heat for a good 4-5 hours after the fire has substantially subsided. It does take a while to get going, but it also does not push us out of the room, which is a finsihed basement, area about 600 square feet.

 

[Bushfire]

Obviously, the temp in the room goes down, but the residual heat seems to keep things warm enough not to bother me. We don't have a thermostat or thermometer in the basement, so I can't give exact numbers, but I do know the soapstone is hot to the touch (too hot to the touch I should say) for a good couple of hours after the fire has gone to embers. I guess I should get a thermometer for the basement (I do have one on the stove pipe, but that's not really a good guide for room temp).

 

[rmcfall]

Would a soapstone stove (like the Mansfield or Heritage) located on an interior wall in a sunken 750 sq. foot family room blast people out of the room? There is 2000+ sq. feet on two levels above (main level accessed by stairs on one side of house going up from sunken family room and the second story being accessed by stairs at the middle of the house on the main floor). I am just wondering if with a soapstone stove we'd be blasted out of the room in order to get heat to the rest of the house?

 

[Woodburner]

I can't resist the urge to throw in a reply. Now, keep in mind, I am biased...I work for HearthStone. I was an independant sales rep for 18 years before going to work for them and have sold steel, cast and soapstone stoves since 1983. So here ya go...

Yes there is a difference between the way soapstone heats and steel or cast iron. You've hit on both so far in this thread. First, it extends the heating cycle. Soapstone can act like a heat battery, storing the excess heat and releasing it over the course of 3-5 hours after the fire has died down. I am talking about heat...not just a little warm to the touch. By storing the excess heat, it also evens out the heating cycle. Instead of getting real hot, then dumping all its heat in the room, then cooling off; soapstone will heat up and maintain a more even temperature for a longer period of time. You will notice a difference. Our toughest customers are those who have been heating with wood for a long time. They expect to feel that hot blistering heat and what we offer is a consistent, gentle heat. They still heat...but its the even heating we are looking for.

Rick Vlahos
Education Coordinator
HearthStone Quality Home Heating Products

 

[saichele]

When we're burning, we basically go 24/7, and with the exception of the occassional long night, keep many hot coals or actual flames inthe stove. This has been with steel and cast stoves. If you do that with soapstone, are you negating the 'battery' effect of the soapstone? Put another way, to get a benefit from soapstone, do you need to have a series of fires, rather than one long, multi-day fire?

Steve

 

[Jfigliuolo]

I really like our soapstone. The even heat is VERY nice. I always hated going to my in-laws who had a cast stove. Blasted me out of the room. Hated it. The one thing you MUST know though. It will take a SOLID hour from a cold/barely warm stove to get decent heating from it.

 

[Woodburner]

I am heating 2400 square feet with a soapstone stove. Realistically, our stove is going about 20 hours a day (I am short on wood this winter, I rely on the furnace for the rest). I find that the "battery" effect still helps because I tend to wait longer before reloading wood. Since the stove is still hot, why throw more wood on the fire? I'm burning less wood now than when I had a cast stove in the house. I can't quantify the number, but as the guy who has to cut, split and stack the wood, I know I am burning less.

 

[Jfigliuolo]

UMMMMMM......NO.

Isulation has NOTHING to do with heat capacity. Fiberglass is an excellent insulator. It holds ALMOST NO HEAT.

Some of what your saying sort of rings true, but the science behind your statements is a little suspect.

 

[Jfigliuolo]

Snipped ... 'scrubs' the heat of combustion at a slower rate as well. Again, anyone who fails to see this is looking at heat transfer throught soapstone colored glasses.
Snipped
Dylan

Oh, kind of wrong again... The soapstone SCRUBS VERY WELL. When I first light up in the AM it takes a LONG time for my flue gasses to get hot. WHY? The SS is taking ALOT of heat from the discharge. Once my tove gts hot the gas temp also rises. A good insulator would have less heat transfer to the medium and therefor hotter gas temp.

I am not saying this is godd/better/ or even desirable. I'm just saying it is what it is. Is SS bettern that Cast/steel/55 gal drum? That's up to each individual to decide.

 

[rmcfall]

While I believe I understand what you are saying with regard to the insulative properties of soapstone, why does it matter if it is called more of a "gentle heat" if that is what the outcome is? Perhaps I am mistaken, but I read the initial paragraph of your post as a criticism directed toward Hearthstone and similar manufacturers and am just trying to understand your point.

What Hearthstone and other manufacturers market as 'gentle heat' is PURELY as result of the insulative (as compared to cast iron or steel) properties of the material with which they construct their product(s). Anyone who fails to see this, has no clue as to what the insulation that they put in the walls and attics of their homes, ie, IT SLOWS THE RATE OF HEAT TRANSFER FROM THE LIVING SPACES. Walls with R-19 as opposed to R-11 inside transfer heat in a more 'gentle' manner. Correspondingly, soapstone 'scrubs' the heat of combustion at a slower rate as well. Again, anyone who fails to see this is looking at heat transfer throught soapstone colored glasses.

There is, however, an upside to this property of a material that causes energy to migrate slowly, ie, it radiates heat back into the materails of the fire resulting in an efficient burn.

And, clearly, soapstone has an almost unparalleled capacity to STORE heat. However, when this is most necessary, ie, AFTER the fire has burned out, and the thermostatically controlled air inlet is OPEN, ambient air is then enterring and scrubbing significant portions of that heat and, correspondingly, keeping the chimney warm.

Dylan

 

[Jfigliuolo]

UMMMMMM......NO.

Isulation has NOTHING to do with heat capacity. Fiberglass is an excellent insulator. It holds ALMOST NO HEAT.

Some of what your saying sort of rings true, but the science behind your statements is a little suspect.

jf,

REREAD my words. Where did I say that insulation had anything to do with capacity??

I said, AND I MAINTAIN, that soapstone is a poor (relative to steel and iron) CONDUCTOR of energy and that, BY DEFINITION, means that it is more insulative.

Do you have a degree in engineering??

Dylan

I understand what you wrote... But i do not agree.

Think of soapstone as an inductor and fire as a DC signal. When a charge is applied, INITIALY it acts like an open circuit. No current or in this case heat is transfered. After the capacitor (Soapstone) is charged it acts like a closed circuit. Electricity (Heat) travel freely. When the electricity (fire) is off, the inductor (soapstone) discharges it's energy.


Now, an inductor is clearly NOT an insulator BUT it act's like one initially. Corespondingly Soapstone IS NOT an insulator BUT IT DOES ACT LIKE ONE when heat is applied.

Now the difference is that Soapstone stores it's energy to be released after the energy is applied.

Steel and cast due the same thing, but to lesser degrees.

I guess the point I am ,making here somewhere is that I think you are mistaking "Heat Capacity" or the ability to store heat with insulation or the ability to reflect heat/energy.

So you get what I am saying? Just be cause heat is not transfered INITIALLY does NOT mean that Stone is not conducting the same amount of energy ONCE steady state is established.

Now I'll give you this... MIGHT stone be less of a conductor than cast or steel? sure. Does Stone HOLD HEAT LONGER than cast or steel? yes.

DOES this make it right for everyone NO.

And not that it means jack... but yeah I am an engineer, RPI class of 90. for whatever that's worth.

 

[rmcfall]

I perceived the marketing to be that the product has the ABILITY to move heat slowly. Guess it depends on how you look at it. Seems like you are saying soapstone is an inferior product because of this...

Okay, I'll 'put it' differently:

'Gentle' heat is a marketing ploy to misdirect focus from a product's inability to move heat quickly.


A large soapstone stove in a well insulated home may, indeed, be adequate to yield comfort.



Dylan

 

[Jfigliuolo]

OK... obviously you think SS is bunk.

Riddle me this.

1. IF SS has a greater specific heat than steel (which it does) which will STORE more heat.

2. IF my gas temp reading on MY stove is the same as YOUR stove for the exact same fire can we agree that the
same amount of heat is LEAVING the system? (I know, you can argue your would be lower...I could do the same)

3. You stove temp is 50 degrees higher than mine (during warm up). ( thus the less/more even heat argument)

4. Where do you postulate the heat is going?

 

[Jfigliuolo]

Snipped...

1. The ONLY parameter relevant to the RATE of heat transfer, here, is CONDUCTIVITY.
2. You are absolutely wrong about steady-state conditions.

I have been VERY careful to choose my words to avoid saying that cast iron or steel is THE right choice for everyone.

Dylan

1. NOT TRUE an object with a higher specific heat WILL TRANSFER ENERGY MORE SLOWLY. That is a fact. It takes MORE energy to get the object to the same T as an object with a lower specific heat. THAT IS A FACT.
Now, get this the object with a higher specific heat will also RELEASE MORE ENERGY AS IT COOLS. That is a fact.

------- EDITED
I need to check this one out. I shouldn't say that "NOT TRUE an object with a higher specific heat WILL TRANSFER ENERGY MORE SLOWLY" is a fact UNTIL I find out for sure. Intuitively it makes sense... But may not be the case.

---------- END


2. Maybe, on this one.


3. Here is a challenge. FIND some proof that Soapstone is a better insulator... meaning it reflect heat better than steel. I will then concede that you are indeed correct on this. I will also try to do the same.


4. You CANNOT argue though that Soapstone does not have an advantage of radiating MORE energy to the room after the fire is out than metal.

I'll give you this also (I'm in the Holiday mood). Lets say Stone does insulate more... fine. It also does hold the heat longer. fine...

Let's agree that it is a trade off one must make. You want long lasting heat? fine. You use sopastone that has a high specifix heat to HOLD more energy. BUT the cost is some that it has more insulating propertied than metal which MAY not be desirable. (The magnitude of which is yet to be determined.)

 

[Jfigliuolo]

I firmly believe that if one was to conduct a poll (tho I'm not exactly sure how the questions would be structured/worded) it would indicate a greater incidence of degradation of stove internals of soapstone stoves than steel or cast iron stoves, and that, if respondents were honest about it, it would further indicate that the degradation was due to over-firing, a practice in which some soapstone owners engage in an effort to push more heat into their living environs. I personally have heard of many such cases.

Dylan

Maybe... Maybe not. People overfire all different kinds of stoves.

Also, this is kind of impossible since if the results aren't what you expect you can argue that people aren't being honest which may or may not be valid.

 

[webbie]

On this matter, we agree.....which is why I mention that which is my experience, ie, I've known those who have severly damaged the internals of their soapstone stoves, and are not too proud to admit that which they felt to be the explanation.

Dylan

Well, since we are bring honest, the HearthStone guy can admit that Dylan is right....earlier models of HearthStone stoves often needed quite complete rebuildings because of certain reasons...

1. They sold BIG in the colder areas of the country, and therefore were used heavier.
2. HearthStone customers tended to be more serious wood burners, again meaning more use and more degradation.
3. (this is a guess) HearthStone found out the hard way that interior components of cast and steel have to be extra heavy due to BOTH #1 and #2, as well as the fact that Soapstone might have caused higher interior temps than some other stoves.

It is fairly safe to assume that current models are designed and built with this in mind.

As far as this thread is concerned, there are good point here, but the real key does become tested efficiency of the stove - that is, if the soapstone was "bad", the stove would test much lower and the stack temps would be much higher.

To my knowledge, they do not test lower, so I would guess that the basic arguements for soapstone do hold.

As far as Marketing terms...WELL, I'M AFRAID ALL OF US ARE GUILTY OF THIS - that's the job of us marketing types - to attempt to easily explain the advantages of a certain item or service. You can't expect HearthStone, HearthNet, Woodstock Soapstone, VC of any company to spend a lot of money creating a message that says:

"Well, our stove is good, but really not as good as you think!" (HA Ha).....

This stuff is not Rocket Science. Efficiency tells the tale.

Mass of a stove, even a cast-iron and steel one, also have an effect. A steel stove in front of an interior masonry wall might have the same effect as a soapstone stone without one....

So, snow snow snow here in western mass, about 8 inches so far and still coming down.

 

[ChrisN]

Man, How does a dumb-ass like me manage to even light a fire in my stove? A titch off subject here, but speaking for myself, I don't think of wood-burning as rocket science. I do congratulate you both on keeping your debate civil.

oh yeah.... School of Hard Knocks, class of 1959-2005 (continuing education program.)

 

[Todd]

[quote author="rmcfall" date="1134118699"]Thanks for the feedback, Todd. So it sounds like once a soapstone stove achieves the desired temperature, it is easy to maintain such a temperature without the peaks and valleys like a cast iron or steel stove. The soapstone seems like a good choice as long as the fires are kept going all the time. How many square feet are you able to heat with your Homestead?

I was curioius about the convection and radiant differences--partly from reading on this site, as well as seeing stoves that are advertised as convection. Morso advertises some of their stoves as convection, and my prior stove (Waterford Ashling) was also advertised as convection so I've never had anything else with which to compare.



Wow! You really opened a can of worms on this topic!

They can all argue til their blue in the face. These are my facts! My house is an open floor plan 1800sq ft (total including basement) ranch. My soapstone stove is installed in a finished walkout type basement. It's on a far end wall about 20ft from the stairwell. I fill the stove about 3/4 full and burn medium to hot depending how cold it is outside. It will hold a fire for about 3-4 hrs this way, and then I let it sit for another 3-4 hrs with hot coals and let the soapstone do the work. At night I pack her full of wood and damper all the way down. When I get up in the morning the stove is still too hot to touch, and all I have to do is rake the coals and add more wood.

Since I have added more insulation and worked at tightening up my house this stove has kept the whole house warm so far this winter. The other morning when I woke up, it was -10 outside and inside the upstairs was 71, downstairs 76. I was thinking of an insert for my upstairs fireplace, but now I think It would be a waste of money.

This stove replaced a small Regency steel stove. I now use less wood, and personally think the soapstone heats better. Also looks nicer than the old black steel box.

 

[webbie]

T. Also looks nicer than the old black steel box.

Well, just like they let that "sex with the student" teacher off easy yesterday - looks Do matter.

Watching her on the tube, can't help thinking the poor 14 year old had little choice! And he'll have some bragging rights with the boys in about 10 years!

Like it or not, we humans are driven by that "looks" thing, and soapstone fills some of that need. The other thing about Soapstone is that it has sort of a timeless style....like a bit retro and unlikely to go out of style. That's a pull!

 

[Jfigliuolo]

Snipped ...
These concepts are FUNDAMENTAL. Heck, jf even has me re-thinking his concept of 'steady-state' to INCLUDE (I think) the stove materials as inductors. If, on the other hand, he is referring to 'steady-state' to refer ONLY to the rate of conduction of heat through the material, then I would have to stand by my analysis, because I fail to see that just because the material has come up to temp, it then transfers energy faster than when cold.

nope, it's the former. I do not propose that the rate of transfer increases due to T changes although, to some degree, it probably does, but not enough to matter anywhere even near the ranges we are talking about. It MAY though at the extremes... funny things always happen there.

 

[carpniels]

HI Engineers and company,

I am a fellow engineer (biological/environmental), but even I have a hard time following the discussion.

I have just bought a Hearthstone II (am rebuilding it at the moment due to overfiring melting the baffle) and ever since I had it, I have been wondering how it would have a greater heating capacity if the temp of the stove doesn't get nearly as high as the cast iron VC Intrepid II I have now. I thought delta T was the important issue here. I guess I am wrong, even though I do not understand it completely.

But I guess the only way to find out it to replace the VC with the HS and see what happens.

I will keep you all informed

Carpniels

PS. As to those hot female teachers doing their students; where were these ladies when I was in high school