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    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
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  1. webbie

    webbie Seasoned Moderator Staff Member

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    Well, my dad is just like that.....

    he told me about a great invention...it would hook on your faucet and generate electric when you opened up the tub or sink water flowing.....

    great idea!

    BUT, when the cost of pumping the water and the cost of the water is figured in, I don't think you'd come out ahead!

    BTW, a contact of mine near here owns a sheet metal shop on a mill pond, and he has really good flow as well as really good drop. Although I am not a engineer, but I am good at google, and I worked the whole thing out for him. It might be worth his while! But this is a major waterfall (dam for the original water wheel, etc.)...

    If my memory serves me well, I think he could generate $40-50. a day worth of electric after he spent about 60K, which isn't bad when you think of it.

    LOTS of potential and real water power around here as it is what powered the industrial revolution in these parts.

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  2. PaulGuy

    PaulGuy New Member

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    Heck anyone who's been to college knows for a fact degrees and education do not make you smart. I've had a few teachers with PhDs who were complete idiots! Some highly educated people have ZERO common sense and couldn't think themselves out of a problem new to their experience. Some people with zero education are very intelligent.

    I have a soapstone stove, I like it.
  3. Rhone

    Rhone Minister of Fire

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    I can't see how soapstone would be worse. I'm thinking about heat transfer. Let's say you have a 1000 degree fire surrounded by 200 degree material. There's a significant temperature difference and that material is going to suck heat out of the fire to try to balance. Let's say you have a 1000 degree fire, and the material surrounding it is 800 degrees instead. Now, there's little temperature difference and little heat transfer to the mediums and I think the heat goes up the flue. Steel/cast iron units quickly rise in temperature and have a balance with the fire's temperature getting to a point there isn't as much heat transfer. Soapstone remains cooler because it takes more to heat it up, so in theory should suck more heat out of the fire. I can think of a real life example since I've been thinking about solar hot water. If you have 2 panels on your roof and want to increase your systems efficiency, you add more storage (water tanks). That's because the water will be cooler for a longer period of time and you get higher heat transfer into colder water than warmer. I think on the same principle giving the same btu's in a fire, if you want to increase efficiency, you increase storage and part of the reason masonary heaters are so efficient.

    Radiant heat attempts to reach a balance with other items in the vicinity. Thinking of the inside of a soapstone firebox, all the soapstone is radiating heat with each other and reaches a sort of equalibrium. A piece of soapstone radiating 10 units into the firebox, and another piece on the opposite side radiating 10 units into the firebox, each piece absorbs each others for a net loss of 0. That's not the case when it radiates into the living area, only a fraction of a percent is radianted back to the stove so almost all the radiant heat is utilized in the living area, what is released inside the stove is for the most part reabsorbed by itself and recycled.

    Next, what about the convective heat when soapstone is all charged up. It has a choice, the firebox usually has coals keeping the air inside the firebox probably 150-300 degrees or it can transfer the stored heat to the living space air of 72-77 degrees. Since heat moves faster to colder areas, it will transfer more convective heat into the living space than the firebox. To maximize, when the fire is only some coals I would think turning the air down will help maintain a higher temp in the firebox and thus more transfer into the living space.

    So, I have to think as Soapstone as being a micro-masonary heater and more efficient because of its storage. Also explains why it takes a long time to heat up, and cool down, but should use less wood from what I understand and transfer more btu's into the living area over cast iron/steel but I admit I'm not the brightest bulb when it comes to technicals and physics.
  4. rudysmallfry

    rudysmallfry Feeling the Heat

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    To answer your question about a Heritage blowing you out of a 750 sq ft room, my Heritage is in a basement about that same size. I keep the oil heat thermostat set at 60. With the Heritage at 400 degrees, the thermostat reads 72. Very comfortable in my opinion. Of course within a few feet of the stove it's hotter, but otherwise it is a nice even heat.
  5. Martin Strand III

    Martin Strand III New Member

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    Gentlemen, gentlemen, gentlemen:

    In previous posts, this soapstone topic has been massaged quite nicely. Now, it seems, it's time to do it again.

    Soapstone acts more like metal in its conductivity and heat transfer properties than other masonry products. That can be good or bad depending on the application. I chose to have no soapstone in my custom masonry heater. Here's why and the poop straight from the man at www.mha-net.org:

    "Soapstone is a unique refractory and masonry material. Compared to a pound of concrete, a pound of soapstone can store approximately 20% more heat. Its main distinctive thermal property is that it has about 4 times the conductivity of concrete or about 6 times the conductivity of soft clay brick. Another way of saying this is that its R value is 1/4 that of concrete. It is somewhat similar to a metal in this respect. This means that a soapstone heater of equivalent mass will heat up faster on the outside surface and reach a higher surface temperature, due to the high conductivity. On the other hand, the higher rate of heat transfer to the room also means that it cools down faster than other masonry materials. Understanding the thermal properties of soapstone gives the heater mason an additional way to handle unusual design requirements when they arise. For example, we use soapstone heat transfer plates in castable refractory bakeoven floors to even out cool spots. A nice feature of soapstone is that it can be carved quite easily."

    How did that feel?

    Aye,
    Marty

    Grandma always said, "If it has testicles or wheels, it's gonna be trouble."
  6. Jfigliuolo

    Jfigliuolo New Member

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    Well. felt pretty good. Didn't support either argument though. Yeah, it's "like metal" but how much? It doesn't quatitatively specify what the R value is compared to metal. That's the info we need to determine if it conducts heat as well as metal (cast iron) in particular or if it acts as an insulator.

    Also I don't think Dylan is arguing that it doesn't holds more heat than similiar weight of metal (at least I don't think so).
  7. Rhone

    Rhone Minister of Fire

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    It's hard to figure things out as it seems every site has a different property and number for soapstone.

    Cast iron has a thermal conductivity of 520, Soapstone 6-7, Face Brick 1.29, and Building Brick 0.72, and firebrick 0.95. That's a measure of how well heat transfers through the material. If that's true, I don't agree with the mha-org saying soapstone is more like a metal in that respect if metal is 80x more conductive. So, what that says is that soapstone does actually "suck" the heat out of a fire rather well, sure 80x worse than cast iron but 5x better than Face brick, 9x better than building brick, and 7x better than firebrick.

    The difference then is the specific heat. Soapstone has a specific heat value of 0.23, building & face brick 0.22, and cast iron 0.16. Specific heat is how fast a substance heats and cools, lower means it heats and cools faster. What you're saying is, you chose a material that takes 4x longer to heat (or maybe 5x if you used face/building brick) and loses that heat to the living area a little faster than soapstone. Why?

    I'm thinknig if soapstone cools at about the same rate as brick (it's a little slower) but transfers heat through itself 5-9x better, whisks that heat throughout itself better, and can store more, it will suck more heat out of the fire, store it in less space, and transfer that heat back slower into the living area making it a superior material. But, like I said I'm not a bright bulb and particularly don't know masonary heaters or the theory behind them. I can only guess that with masonary heaters you don't actually want them to charge up quickly? Which, I don't understand why not soapstone because masonary heaters burn fires incredibly fast & hot, I'd think you want a fast absorbing and fast transferring material like soapstone to suck the heat out while it's hot and get the most out of it, then release it slowly and it does release slower than brick and probably concrete (couldn't find numbers for concrete). Maybe that's the theory behind soapstone stoves, maybe masonary heaters work on a different philosphy? I do know they have long channels surrounded by a lot of mass... maybe they don't want to have all the heat sucked out as soon as possible rather try to have a little bit sucked out over a longer distance so you get a bigger area more evenly heated. I'm just thinking aloud.
  8. Eric Johnson

    Eric Johnson Mod Emeritus

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    I'm a magazine editor and in my experience, Phds are some of the worst writers. And the longer the resume, the more you're gonna wince. Engineers ain't much better, though you guys went to the good schools, which is probably why you are both above average engineering communicators.

    Ever since reading that modern stove glass actually a transparent ceramic material, I've been wondering what a stove cast out of that stuff (if that's how they do it) would work. Make a pretty nice looking stove if you used different colors, etc.
  9. Rhone

    Rhone Minister of Fire

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    Hmm.. my inexperience with physics really shows. I didn't understand what you're trying to say Dylan. Was I supposed to mention water and say "Speicific heat is how fast a substance heats and cools compared to water, the lower the value the faster the substance heats and cools". That doesn't change the meaning of the post. Materials with lower specific heat numbers heat faster and cool faster than materials with higher specific heat values.

    Just thought of something though to give people an idea. Does that mean cast iron with a 0.16 specific heat value cools or gives off its heat 6.25x faster than water? Brick 4.5x and soapstone 4.3x?
  10. Martin Strand III

    Martin Strand III New Member

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    Guyz:

    Comparing a masonry product (soapstone) to metal (cast iron and steel) is not exactly like comparing apples to apples; more like comparing apples to appaloosas (horses - they eat apples...).

    Metal stoves (cast iron and steel) have high heat transfer efficiencies. This property explains why a fire in a metal stove needs to be controlled, by intake air, to prevent overfiring and damage to the stove as well as overheating the room. Unfortunately, decreasing air supply also decreases combustion efficiency in the stove (this problem is inherant with all woodburning metal stoves).

    Masonry products (soapstone, brick et al) have moderate heat transfer efficiencies (this is desirable for heating devices inside your home). Addition of these materials to the firebox of metal stoves helps insulate the metal stove against thermal damage, allows higher firebox temperatures to increase combustion efficiency and helps retain heat in the stove to slow heat transfer to the room. Some companies offer extra masonry (soapstone or granite panels, plates) outside the firebox of metal stoves to help further slow heat transfer to the room. Woodburning stoves made entirely from masonry (masonry heaters) are the ideal for a wood burning device by having high combustion efficiency (1500*F or better fires) and moderate heat transfer to slow heat delivery to the room.

    Hope this helpz.

    Aye,
    Marty
  11. Eric Johnson

    Eric Johnson Mod Emeritus

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    See, Marty actually writes in a way doesn't intimidate or put people off with a lot of BS and jargon and crackpot theories. And he makes sense.

    I'd be willing to bet he's not an engineer.

    Aye!
  12. Martin Strand III

    Martin Strand III New Member

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    Dylan:

    Please don't be offended by me. I'm just saying what others have said. I'm just saying what others have written. I'm just saying what makes sense to me.

    Read about it yourself here:

    http://www.tempcast.com/wood/woodplan.html

    Keep what makes sense to you and fling the rest.

    Aye,
    Marty
  13. Rhone

    Rhone Minister of Fire

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    I think it all came up when someone said Soapstone stone is "insulative". Like, water is extremely insulative... it holds a lot of heat. I think most take calling soapstone insulative as if the soapstone insulated the firebox and causing your heat to go out the chimney. If you change that posters term for insulative with "heat storing" instead they sorta make sense.

    We were all saying soapstone stoves let you burn shotter hotter fires without getting roasted, releasing it over time, and you get more btu's out of your wood and into the living space over other types like firebrick, steel, and cast iron. They also made a good point about soapstone, you do run them hotter because they are cooler. They put more heat into the living space but it is subtle. I got used to being blasted with tons of heat of my two past stoves... I don't get that now that I have a soapstone insert. They do take a while to heat up and cool down and take adjusting to. I got used to my stoves, where the area felt like it was 90 for a period of time, and when it felt like it was 65 I'd reload and it would feel like it was 90 again. With the soapstone, I load it and the area gets to 74, when it gets to 72 I reload and it goes back to 74. Doesn't have near the temp swings, but also if starting from a cold house (60) it does seem to take a long time to warm the area with it. I do use less wood, and my temperatures more consistent. They are a totally different experience, throw what you've done and learned about steel & cast iron stoves away. The bit I have a soapstone insert and went from a radiant heater to a convection heater also has taken getting used to.
  14. Martin Strand III

    Martin Strand III New Member

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    Rhoneman:

    I dig everything you said in your last post except what you said about "firebrick, cast iron or steel". You are putting an apple (the firebrick) in the apaloosas wrong end.

    Firebrick is masonry, not metal and cannot be included as a metal or really compared to a metal.

    And, "insulating" is a RELATIVE term. Firebrick insulates as does soapstone (so does cotton in other applications); firebrick probably more. The difference is in the details. Refer to the numbers.

    As we all are trying to make sense out of the limitations of our metal stoves and get te most " 'back' for the buck", keep stoking your coals and stay warm.

    Aye,
    Marty
  15. Mike Wilson

    Mike Wilson New Member

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    I think JFigliulo has it right... and I'm not going to post my entire CV here to back up my opinion.

    As for the rest of the thread:

    Attached Files:

  16. rmcfall

    rmcfall Feeling the Heat

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    thanks!

  17. webbie

    webbie Seasoned Moderator Staff Member

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    >>>>>Dylan...who doesn't wish to even imply that your (or anyone's) home is not comfortably heated whichever stove you

    ------------use.[/quote]

    OK, guys, please end the thread here...bickering does not add any relevant information. Take it to private messages or email...thanks.
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