soapstone and duration of burns

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rmcfall

Feeling the Heat
Hearth Supporter
Nov 28, 2005
308
All my questions about soapstone and here is another one (sorry)....

Do people generally burn short, hot fires in soapstone stoves, or can you burn longer, steady fires?
 
So far I've done both - although the short burns are almost certainly longer than the ones people have in regular stoves as it does take a while to warm the stove and have adequate draft. I haven't done enough burning with the stove to say which method is best - I suspect that depends on what you're trying to achieve (taking the chill out, or maintaining a constant room temperature.
 
That's the theory behind soapstone. The shorter, and hotter your fire the more efficient. The problem with non-soapstone stoves is you'll roast yourself out of the house burning extremely hot fires.

Soapstone stoves/inserts aren't particularly well suited for letting them get cool and getting another fire started from kindling. I have a soapstone insert that has all the sides but the top (secondary burn & flue pipe) & front (glass) covered in soapstone. I thought my unit would be more like a soapstone/cast iron hybrid, but it is very much like a soapstone stove. The first fire from a cold start I call a sacrificial fire. Most of its heat is spent warming up the unit. The soapstone sucks the heat slowing down the secondary burn from taking off so I compensate with additional amounts of kindling, the glass gets dirty, and it doesn't burn as well as subsequent fires nor puts out as much heat as them. 4 hours after lighting on max air my soapstone insert is fully charged and heating but the fire is spent, and if I don't reload it's another 2-3 hours and the unit cools down. They say since I burned a fire in 4 hours it will still put more btu's in your living area than a cast iron one, but it must take a long time and the first fire doesn't burn necessarily well. It's the next fire and all following fires I think part of the soapstone secret. After the first fire is a bed of coals ready for more wood, the soapstone is putting out tons of heat. When I open that door and throw logs on the coals my hand feels like it's going to vaporize from heat releasing from the soapstone even though the fire is only some coals now. Within a few minutes and that temperature all the new wood combusts, the secondary burn kicks in a minute afterward, and the fire is in tip top burning shape in minutes of reloading from a bed of coals. The second fire and any thereafter burns so good and fast, and the secondary burn starts so fast I get practically all the heat out of any more loads and don't have to feed it much to keep it putting out a lot of constant heat.

With soapstone you burn it at a higher air setting than normal. I think I get diminishing returns the less air I give it. For example, I light a fire at 10PM and it's burned by 1AM (3 hours). That fire is super hot, it burns very efficiently and the soapstone gets supercharged, cleans my glass and the soapstone carries me over for 3 more hours. At 5AM my house is around 74-75 degrees still. Let's say instead I burn a fire and slow the air down to 5 hours. Now, as with any unit soapstone or not the fire is cooler, it's not burning as completely, there's some unburned heat going out my chimney, the secondary burn isn't operating as well, and the soapstone isn't charged up as much with the cooler fire and can't carry me over as far. That fire also being done and over, at 5AM this time my house is around 71-73 degrees by burning it slower. It is more efficient though and you get more heat into the living area burning a slow fire for 5 hours and using the soapstone to coast for 2, than using a non-soapstone unit slowing the air down to burn over 7 hours. Another part of the soapstone's ability to let you burn hotter more efficient fires and coast some so you use less wood than non-soapstone units.

You have A LOT of square footage to be heating and sounds like an inefficient house. It's unlikely one stove will be able to completely heat your house. At least I think you're heading in the right direction because your choices are rather limited. You can't get an insert, large convection wood stoves I've personally found them to be wanting, and a cast iron/steel freestanding stove is the most probable to roast you out of that room and be the least likely to heat the place. There's only one thing left, a soapstone stove and I think is the right choice if you can afford it. The question becomes what size. Go too small, you'll always be burning on maximum air, constantly having to put more wood in it, putting more wear & tear on your parts, and not supplement your heating as much as you'd hoped, but your efficiency will be high and heat output constant. Go too big, and you risk it will heat your place/room too much and cause you to constantly let the fire die and later have to start it from scratch when the soapstone is cool. That's a lot of kindling and that first fire while your unit is cool with soapstone never burns as well as the following fires. A properly sized soapstone stove is simply a pleasure to use, and very critical. Truth be told, the perfect size is one where the coldest days it can barely (or may not be able to) keep up. Sort of like your furnace/boiler, the perfectly sized furnace/boiler is one that will have to run 24 hours/day on the coldest days and just be able to keep you comfortable.
 
It all depends on the weather for me. The colder it gets outside the hotter the fire I burn. During the day I like to fill up the fire box and burn hot, let the fire die down to coals and let the soapstone heat for a few hours. If the house temp is where I want it I don't put more wood on until I have to. I also monitor the stove temp pretty close. If it rises above 600 I'll turn the air down.

In the evening when I go to bed, I fill her up, burn hot, and damper all the way down after about 15 min. This will give me a long slow burn keeping the house at comfort level til morning, and lots of coals in the morning to start burning again. It will take you awhile to see how the stove burns best for you. Lots of trial and error.
 
Rhonemas said:
That's the theory behind soapstone. The shorter, and hotter your fire the more efficient. The problem with non-soapstone stoves is you'll roast yourself out of the house burning extremely hot fires.
I think your info is wee bit off . We have run really hot fires in our 97,000 BTU P.E. summit when the temp was below "0" , with the ceiling fans and blower we kept our house 74 in the stove room ( 17 X 24 ) 72 in the kitchen and 70 upstairs . We wer NEVER "roasted out" How many BTU's is your stove Rhonema ? I am understood that it is better to heat a whole house with a steel stove or cast and a Soapstone is for more of a radiant heat for more of a even heat in a confined area . You just need to know how to use a stove so you dont get "roasted out" I would guess that if you didnt know how to run your furnace and set it at 90 for some reasion you would get "roasted out" . Rhonemas i believe you are thinking of "pot belly stoves" when you tell somebody that they will get roasted out.
 
Thanks everyone for the tips on how they burn their soapstone stoves. They sound really good, and I imagine they will hold a hot bed of coals for a real long time.

Rhonemas--I could fit an insert (or two) in this house, but I guess I like the idea of a stove. With my previous stove I really enjoyed cooking on it every now and then...such as filling a dutch oven with ingredients for an omelette at bedtime so it would be ready in the morning for breakfast.

I just wish I was getting a stove this winter instead of next winter!
 
You have to consider the stove is damped down for the overnight burn, and then the use of a trivet further decreases the heat the dutch oven receives.
 
Roospike, it's not easy to explain and I've tried in the past. The roasting in particular cast iron & steel is the radiant heat, I've had a cast iron stove & steel stove for the past 25 years, used them to heat my house. The radiant heat from freestanding stoves makes me feel like the air temperature is 10-15 degrees warmer than it is. It's like the difference of being in the shade with a thermometer telling you it's 75 degrees, and the difference of being in the sun at noon with a thermometer telling you it's 75. The air temperature is the same but you sure feel like it's hotter being in the sun than the shade. If you apply that to stoves (steel & cast iron) they let you feel comfortable around the stove when the air temperature is 60-65 degrees, add in their radiant heat makes you feel like it's 10 - 15 degrees warmer and you're nice and comfy. The problem is, I had to keep the air temperature around my freestanding stove to be 75-78 degrees in order for there to be enough to heat my house. That's what a thermometer said, but add that freestanding stoves add 10-15 degree radiant heat around it and you "feel" like it's 85-90 around the stove. I'd sweat near it or reloading it even though the air temp was only high 70's. You have to have a particular situation or layout to work with a freestanding steel/cast iron stove, use it for house heating, and not be roasted. If I wanted to feel comfortable around my steel & cast iron stove, I'd had to lower the air temperature to 65, then with the 10-15 degrees radiant heat I'd feel like it was 75-80 which is tolerable. But, that 65 degree air temperature meant I was insufficiently heating the rest of my house. If you have a big room, I'd imagine it can be successful because the further away you are from the stove, the less the radiant heat. You can surround the stove with obstacles to block it which would obstruct your view though, or get a convection wood stove that is really awesome. But, I can't find any large ones that have convection shields on all sides. By the sounds Roospike, you have it on 1 side (the back) and that was smart, any helps. Can you imagine having 5 instead? Those shields prevent this "radiant heat" making you feel like it's 10-15 degrees warmer so you can have the air temp in that room be 75 and it will feel like it's 75 but also heat additional amounts of air that spreads through your house. rmcfall has a small room where he wants the stove and I don't think he has a chance of not roasting himself with a freestanding steel/cast iron stove and help heat the other 2000+ sq ft. Not at all.

I don't have a soapstone stove, mines a soapstone insert. I believe soapstone's tendancy to have a lower temperature and spread it over time means that it's radiant heat may make the room feel like it's only 5 degrees warmer instead of 10-15 of the steel/cast iron. If you have to keep the air temp in that room at 75, a soapstone stove adding only a small amount of radiant heat will make it feel like it's 80 and that's tolerable. I'd imagine over the long haul a soapstone stove contributes a decent amount of convection heat as well per burn. An insert with heat shields on 4-5 sides, will probably be able to heat his house as their blowers force all the air in his house to be heated 150-200 degrees every 2 hours and they do particularly well with poorly insulated and drafty houses. But, they stink for cooking and without their blowers talk about taking the wind out of the sails, and inserts aren't particularly attractive in summer... like at all. rmcfall, I recommend if you go the soapstone route, you spring for the optional rear heat shield and blower if it's not too much.
 
Rhonemas said:
An insert with heat shields on 4-5 sides, will probably be able to heat his house as their blowers force all the air in his house to be heated 150-200 degrees every 2 hours and they do particularly well with poorly insulated and drafty houses. But, they stink for cooking and without their blowers talk about taking the wind out of the sails, and inserts aren't particularly attractive in summer... like at all. rmcfall, I recommend if you go the soapstone route, you spring for the optional rear heat shield and blower if it's not too much.

I'll have to consider an insert. With regard to a stove and attached blower, does a blower do any better than a ceiling fan in the same room? And how noisy are insert blowers, as well as the optional blowers for stoves?
 
Still sounds like you had a pot belly stove , ha . The only radiant heat i get off my steel stove is the glass as how it was made. The fan(s) turn the other heat and i do not get the radiant heat problems that you speak even with out the fan(s) unless i am right in front of the glass . Unsure of what old stoves you have had in the last 25 years but it sounds NOTHING like the new EPA stove i am running now . I can not take sides on the cast stoves because i have never owned one but from what i have read the cast stove throws off radiant heat . Now i might agree with what you say on a steel stove from the 1970's and older but you have to compare apples to apples . You cant not compare a soapstone stove of today to your grandpa's cast or steel stove of yesterday or even the one you used 25 years ago. Apples to apples my friend.
 
I didn't have a pot belly stove, my Aunt did. You and I are on the same page as we're both confused. My steel stove of the 70's, sure was difficult to be around but it was only 70,000 btu's. Your stove is built similar, it's steel and square and probably even has the same size firebox but the secondary burn gives you the boost from 70,000 btu's without it to the 97,000 with it. I don't understand how 97,000 btu's steel stove doesn't roast but a 70,000 btu steel stoves does. Regardless, I'm glad. The pot belly stoves diffuses the radiant heat since it travels in a straight line from a plane. Since pot-belly stoves don't have a plane (flat surface), rather are round the radiant heat is equally transmitted all around it reducing it's intensity equally everywhere and eliminating hot & cold spots, and should reduce roasting in those hot spots. Square stoves like the one I had focus it, as the flat sides channel the radiant energy to emit straight out from them and give nearly no radiant heat diagonally. Stand diagonally to a square stove and wait a minute, you probably won't notice any radiant heat. Instead, move the same distance but directly on one of the sides and give it a minute. I couldn't give it a minute I felt like I was burning. It's that phenomina that lets you put square stoves diagonally into corners and you can have it closer to the wall than putting it flat. My in-laws bought a new EPA cast iron firebrick lined freestanding stove 4 years ago, and have the same problem. If they use it to heat their house, the open area it's in feels too hot. If they keep it cooler so the section it's in is comfortable, it's not putting enough heat for the rest of the house. So they turn it up and gotten used to feeling like it's the desert at noon in that part. When I visit them, I told my wife I think her parents are trying to kill me and periodically go outside to cool off, their stove is new, EPA. I'm happy Roo you don't know what I'm talking about, that implies your stove is in a situation that is condusive to home heating without feeling the roasting affects. My in-laws and I, were not so fortunate.

Well rmcfall I think an insert will be the one that will be able to most likely heat your house or offset your heating bill but isn't what you want. I think a ceiling fan would be just fine instead of the blower and was one of the top rated items to work with a stove. Don't think about an insert too much, sure they may be the best to heat a house but not the only units that can heat a house and Roospike points that out, there are other things involved. An inserts blowers sound like an AC on medium, a blower on a freestanding stove is smaller than an inserts and probably more like an AC on low. Do your research, I can tell you won't be happy with an insert, I think the soapstone stove is the way to go and forget the shield and blower since you have the ceiling fan. If you're looking at soapstone though, look at firebox size. I see a soapstone stove that's larger than the Pacific Energy Summit, is more efficient, has more surface area, holds and burns more wood, but only rated at 80,000 btu's the summit 97,000 btu's. You have to concern yourself with sustainability. My guess is if you get the summit to 97,000 btu's I bet it would put something like 50,000 btu's one hour, 97,000 btu's the next, 60,000 btu's the third for a total of 207,000 btu's over 3 hours. If you got the soapstone stove to 80,000 btu's I bet it would go something like 70,000 btu's one hour, 80,000 btu's the next, 70,000 btu's the third. In the end, the soapstone put out a little more btu's over the course of 3 hours and it should. It's more efficient and has a bigger firebox. So, there's more than just max btu's when looking at a soapstone stove, I like to often judge by firebox size, and good luck.
 
Thanks for all the feedback, Rhonemas.
Rob


Rhonemas said:
Well rmcfall I think an insert will be the one that will be able to most likely heat your house or offset your heating bill but isn't what you want. I think a ceiling fan would be just fine instead of the blower and was one of the top rated items to work with a stove. Don't think about an insert too much, sure they may be the best to heat a house but not the only units that can heat a house and Roospike points that out, there are other things involved. An inserts blowers sound like an AC on medium, a blower on a freestanding stove is smaller than an inserts and probably more like an AC on low. Do your research, I can tell you won't be happy with an insert, I think the soapstone stove is the way to go and forget the shield and blower since you have the ceiling fan. If you're looking at soapstone though, look at firebox size. I see a soapstone stove that's larger than the Pacific Energy Summit, is more efficient, has more surface area, holds and burns more wood, but only rated at 80,000 btu's the summit 97,000 btu's. You have to concern yourself with sustainability. My guess is if you get the summit to 97,000 btu's I bet it would put something like 50,000 btu's one hour, 97,000 btu's the next, 60,000 btu's the third for a total of 207,000 btu's over 3 hours. If you got the soapstone stove to 80,000 btu's I bet it would go something like 70,000 btu's one hour, 80,000 btu's the next, 70,000 btu's the third. In the end, the soapstone put out a little more btu's over the course of 3 hours and it should. It's more efficient and has a bigger firebox. So, there's more than just max btu's when looking at a soapstone stove, I like to often judge by firebox size, and good luck.
 
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