Soapstone stoves take longer times to heat up???

[Backwoods Savage]

Rather than trying to discuss it all scientifically, why not just see the stove in action?! I have no way of measuring btu's that come from a stove, but I do know what heat feels like. I also know that I can build a really small fire using 3 small splits, let that heat the house in the evening or early night (this fall is when I'm referring to) and the next evening when I go to light a fire, that stove is still warm. Not warm enough to heat the house that night, but still warm. That is why we only use 3 small splits; otherwise, the house would be too darned hot both that night and into the next day....or we'd be opening doors and windows.

I also know that we used to use anywhere from 4 to 6 cords or more of wood during a winter (wood heat is our only source of heat) and after getting the soapstone stove, last winter we burned less than 3 cords and stayed a whole lot warmer.

I also scoffed at the "soft heat" they talk about with soapstone stoves. Heat is heat, after all! But, there definitely is a difference. I can't measure it, I can only feel it. How many btu's is that worth? I don't know and don't care.

 

[raybonz]

Rather than trying to discuss it all scientifically, why not just see the stove in action?! I have no way of measuring btu's that come from a stove, but I do know what heat feels like. I also know that I can build a really small fire using 3 small splits, let that heat the house in the evening or early night (this fall is when I'm referring to) and the next evening when I go to light a fire, that stove is still warm. Not warm enough to heat the house that night, but still warm. That is why we only use 3 small splits; otherwise, the house would be too darned hot both that night and into the next day....or we'd be opening doors and windows.

I also know that we used to use anywhere from 4 to 6 cords or more of wood during a winter (wood heat is our only source of heat) and after getting the soapstone stove, last winter we burned less than 3 cords and stayed a whole lot warmer.

I also scoffed at the "soft heat" they talk about with soapstone stoves. Heat is heat, after all! But, there definitely is a difference. I can't measure it, I can only feel it. How many btu's is that worth? I don't know and don't care.

I hear ya Dennis and I too am sold on your stove... Hope to see one in action sometime... They make them about 3 or 4hrs from me.. Personally I find them very attractive too..

Ray

 

[Todd]

Heat stored in 300lbs of soapstone with an average temp of 450, with a room temp of 70 is 25,000 BTU's.

I've read a lot about these staying hot for hours after the fire is out but it doesn't make a lot of sense to me. First of all when the fire goes out the stove is not going to have an average temperature of 450. More like 200 if your lucky, which, based on 25000 BTU at 450, would mean the stove at 200 would have about 10,000 BTU stored in it. This is equivalent to just over a pound of wood. Also based on the surface area of the fireview (about 2.4m2) the unit, at that temperature, would radiate about 5000 BTU/h. So the question I have is how does a stove that has 10,000 BTU stored, and is radiating 5000 BTU/h stay hot so long.

Maybe it's not exactly releasing 5000 BTU's per hour? Just because at 450 you get 25000 BTU's doesn't mean at 225 it holds half of it does it? Probably more to it than that maybe, maybe not, I don't know. Your right, not alot of heat coming off this stove at 200 degrees, but it's still too hot to the touch and all that's left inside the stove is a coal bed at that temp. This is where my stove is after 12-14 hrs after a full load burn that was as high as 600 plus. It's enough heat to keep my house at desired temp. If I let it go out it will drop off slowly for a few more hours. It doesn't stay hot forever and 200 degrees won't heat your house but I've burned similar sized steel stoves and they were stone cold by this time. Both stove materials will release the same amount of BTU's, but soapstone does a better job at evening out the heat in a longer run so you don't have the ups and downs like steel or cast iron.

 

[bokehman]

Rather than trying to discuss it all scientifically, why not just see the stove in action?!

Physics doesn't lie. My guess is there is another mechanism in play. Maybe people just think the fire is out because the cat is out but in reality there are still some embers burning cool in the bottom.

 

[bokehman]

Just because at 450 you get 25000 BTU's doesn't mean at 225 it holds half of it does it? Probably more to it than that maybe, maybe not, I don't know. Your right, not alot of heat coming off this stove at 200 degrees, but it's still too hot to the touch and all that's left inside the stove is a coal bed at that temp.

25000 is what is stored in the mass, not what it is radiating. By the way 450 isn't double the temp of 225. Don't forget temp starts at absolute zero so 450F is 910 degrees above absolute and 225F is 685 degrees above absolute. As temp increases radiated heat goes up by the power 4. So at 450F it's radiating just over 3 times what it does at 225.

 

[Heat Miser]

My soapstone Mansfield takes about 45-60 minutes to get up to usable heat output. My old cast iron VC Defiant took about 30-45 minutes. It's a negligible difference in real life and once I'm on true 24/7 burning it doesn't matter at all.

I agree with others that the soapstone provides a better and more consistent heat. Not only do I need to reload it less often, but it heats up our multi-story home more evenly than the cast iron did. When I wake in the morning after about 12 hours of burning the stove top temp is around 200 degrees. Not enough to provide a house warming heat, but more than enough to ensure a quick re-light with the coals and some dry wood. My old cast iron stove would be almost completely cold after 12 hours. I've noticed that our house stays more consistently warm with the soapstone stove at the end of the burn cycles because of the slower heat release.

 

[Martin Strand III]

Rather than trying to discuss it all scientifically, why not just see the stove in action?! ......... I also scoffed at the "soft heat" they talk about with soapstone stoves. Heat is heat, after all! But, there definitely is a difference. I can't measure it, I can only feel it. How many btu's is that worth? I don't know and don't care.

FYI: There are different heat mechanisms. You may want to review this topic I wrote earlier here:

https://www.hearth.com/talk/threads/25967/P44/#276348

Also, the banter about soapstone holding heat longer involves the specific heat of the material along with thermal mass (the heavier, the better). An extension of this would be the fact an all soapstone masonry heater (aka a heat bank) weighing 9500 lbs will heat up slower and hold heat much longer than a smaller metal stove with soapstone siding that weighs 600 lbs or so.

Aye,
Marty

 

[Backwoods Savage]

Aye Marty. You are right!

 

[Martin Strand III]

Aye Marty. You are right!

Yeah. I know...

Aye,
Marty

 

[Rich L]

We've been basking in summer temperatures this week but this morning it is back to reality. It is cold both inside and out! So...I started the stove this morning again after being out for 4 days.

When I struck a match to light the kindling, I looked at the time. When the stove top reaches 250 is when the cat. is engaged. Well, I was just a little late as the temperature reached 280 degrees when I engaged the cat. Total time? 30 minutes exactly. So, maybe I could have reached that temperature a little sooner with a steel or cast stove, but is a few minutes really worth arguing about? Is it an issue at all? I think not!


EDIT: The fire was started with 6 pieces of kindling (soft maple sized about 1" x 1"). When that started, I added 3 small splits of soft maple. That is what is still putting out the heat as this is being written.

Morning Brother Backwoods,I'm enjoying your thread and I must agree that my Fireview which I've had since September takes about 20 minutes to reach 250F then I engage the cat.I start with a good amount of dried kindly and the stove heats up very well.I replaced a Pacific energy Summit with the Fireview and I am now a toasty and contented bear.
I also agree with Mr.Heat Miser regarding the amount of time it takes for the Mansfield to start generating good heat.My Mansfield which I have in the cellar takes about 40 minutes to really start producing serious heat.Maybe because the Mansfield is larger than the Fireview.

 

[Backwoods Savage]

Thanks Rich and you will be enjoying that stove for many years! Now we're sending some cold air your way so you can use it even more! Darned cold here right now.

 

[Rich L]

Thanks Rich and you will be enjoying that stove for many years! Now we're sending some cold air your way so you can use it even more! Darned cold here right now.

Thanks for the compliments and the cold air your sending.

 

[Todd]

I replaced a Pacific energy Summit with the Fireview and I am now a toasty and contented bear.

Your going to have a very hard time convincing the Summit cult here that a smaller soapstone stove is out performing a Summit. Me thinks it the lack of radiant heat from the Summit.

 

[Todd]

How can the heat radiate inside and out the flue? The fire is inside and radiates outward. The efficiency numbers are the same or in some cases better than other materials. That means soapstone releases the same BTU's but over a longer more even way.

 

[Rich L]

I replaced a Pacific energy Summit with the Fireview and I am now a toasty and contented bear.

Your going to have a very hard time convincing the Summit cult here that a smaller soapstone stove is out performing a Summit. Me thinks it the lack of radiant heat from the Summit.

Maybe it's just my house.It seems to prefer soapstone stones instead of cast and steel stoves.the only other stove that I had success with in this house was the old Hearthstone II.Anyhow if you've never owned a soapstone I don't know how I can convince anyone otherwise,though you know what I mean since you're a contented owner of a Fireview.

 

[Bobbin]

Very interesting read. We too have a Woodstock Fireview in our home. We jokingly refer to it as our "first major appliance", as it was purchased in late 1991 ($1500!) well before we replaced the 1966 apartment size refrigerator (with a freezer compartment!). In the years hence we've come to love the stove so much that we purchased a Woodstock Classic for the new studio. I can't say enough good things about the Woodstock Soapstone Co. and their handsome and efficient stoves.

Many of our friends are skeptical of soapstone until they've come to visit and watch/feel our stove in action. We invariably get the question/comment about it taking longer to "heat up", too! Visitors often express surprise at how little time is required to get it up and running and operating at good efficiency (I'll time it when I fire it up in a little while). We start our stove the same way you do, Backwoods. We don't use the stove exclusively to heat the house, but in combination with the boiler and thermostats set low in unused areas it keeps our heating budget nicely under control. We burn roughly 1-1 1/2 cord/year; the amount of use the studio will receive will increase that amount, obviously.

And the soapstone does deliver a soft, uninsistant heat over a long period of time. You do notice an increase in warmth when you are next to the stove but it's not same sort of intense increase you feel with a metal stove. We always have a nice bed of coals to start a new fire long after the initial one has died down. Interestingly, even when the stove is really crankin' you can still "bounce" a finger off the surface of it with no immediate burn. When one of our present pride was a kitten she made the mistake of jumping on the stovetop... she flew off it instantly and when we checked her paddy-paws there was no evidence of a burn, nor did she show any signs of distress. (She's not made that mistake since!)

 

[Bobbin]

20 minutes to reach 300 degrees on the stove top thermometer and that's the point at which we typically engage the catalytic combustor. 5 minutes later and it's rising steadily. The stove is burning efficiently and putting out plenty of heat.

 

[Todd]

Hello Bobbin,
Nice to hear from another happy Woodstock owner. One question for you, since you have owned the stove since 1991, how many times have you replaced the cat?

 

[Heat Miser]

I just started my Mansfield stove from dead cold to full-temp. Here are the times/temps from the stove top thermometer:

Flue Temp remained ~850 degrees within 15 minutes after startup.

200 Degrees - 25 Minutes
300 Degrees - 30 Minutes
400 Degrees - 36 Minutes
500 Degrees - 43 Minutes
550 Degrees - 47 Minutes
600 Degrees - 55 Minutes (approx.)

I don't run the stove hotter than 4-500 degrees which is my preferred "cruising" temperature. The peak up to 600 is just the residual heat working through the stone before I shut the damper down to bring the flue temp back to my normal range.

In my experience, the idea that soapstone stoves take a much longer time to heat up compared to other materials is not correct. Any stove that heats up to 500 degrees in 45 minutes is completely reasonable in my opinion. I don't think my old cast iron stove heated up that much faster.

Fire was started with a "top-down" configuration. Larger pieces on bottom, smaller in middle and a Super Cedar fire starter with some newspaper on top to make a delicious wood sundae.

 

[Bobbin]

I'm pretty sure we've replaced the catalytic combustor twice in the time we've owned the the stove. Cleaning it out regularly is part of our "maintenance routine". I take it outside, reverse the vacuum cleaner and blow the accumulated dust into the backyard (close the door and check the wind direction first).

If we notice a decrease in the heat the stove is putting out we'll start by cleaning the combustor and go from there. We are also very careful about what we put into the stove as burnable. We've never used the stove as a disposal, it's fed newsprint and good, clean, dry hardwood and that's it.

I know people often have negative feelings about catalytic stoves, but in my experience it's really unwarranted. Yes, the combustors must be replaced periodically, but if you take care of them and use the stove wisely it shouldn't be a yearly expense and it's certainly not difficult to do.

 

[edthedawg]

I just started my Mansfield stove from dead cold to full-temp. Here are the times/temps from the stove top thermometer:

Flue Temp remained ~850 degrees within 15 minutes after startup.

200 Degrees - 25 Minutes
300 Degrees - 30 Minutes
400 Degrees - 36 Minutes
500 Degrees - 43 Minutes
550 Degrees - 47 Minutes
600 Degrees - 55 Minutes (approx.)

I envy your Wood-Fu. I seriously need an experienced Hearthstone user to come over and show me how to get the Heritage up that hot. :ahhh: Not that I want to do it often (yet) but to not have the ability right there at my fingertips... just a tad disappointing... :red:

Two actual queries:

1 - What do you use to monitor your flue temp? Can't be an IR therm or a surface mount Rutland or anything w/ those temps.

2 - OK this is more of a theoretical... Since I know I have some excess moisture in the wood, I wonder about possibly trying some fires w/ either dry store wood or some bio-brick / enviro-log type of product, and seeing if i get remarkably different stovetop temps that way. I'd be curious in hearing how that's worked out for people. As my curiosity grows, i'll probably have a story of my own to share o nthis topic.

 

[bcnu]

hey Ed...dawg
I haven't tried any of the biobrick type products- but might just as an experiment.

Last year, my first as a burner, I had trouble getting the Homestead up to 350 let alone 400+. This year, no trouble to get quicker higher heat. The reason - Dry wood. Using Poplar right now and have fir ready + oak for the cold weather.

 

[Heat Miser]

I envy your Wood-Fu. I seriously need an experienced Hearthstone user to come over and show me how to get the Heritage up that hot. Not that I want to do it often (yet) but to not have the ability right there at my fingertips… just a tad disappointing…

As the other poster said, it sounds like your wood is a little wet. Dry wood has no problem getting very hot if you leave the damper open.

Two actual queries:

1 - What do you use to monitor your flue temp? Can't be an IR therm or a surface mount Rutland or anything w/ those temps.

I use a Fluegard probe thermometer (about $20 online). My pipe is double walled to the chimney so you can't get an accurate reading with a surface thermometer from it. The install literally took five minutes to do (drill two holes and insert thermometer) and now I have a much better idea about the correct temperature.

On a soapstone stove you really should have a flue probe thermometer IMO. The soapstone takes many minutes to show temperature changes in the firebox as the heat works through the stone. You could be running it way too hot but not realize it until it's too late. You could also be too cold but not realize it until the fire has gone down too much. The flue probe shows changes almost instantly to the burning going on inside the stove. I also use a stove top thermometer as well just to keep an eye on the surface temps.

2 - OK this is more of a theoretical... Since I know I have some excess moisture in the wood, I wonder about possibly trying some fires w/ either dry store wood or some bio-brick / enviro-log type of product, and seeing if i get remarkably different stovetop temps that way. I'd be curious in hearing how that's worked out for people. As my curiosity grows, i'll probably have a story of my own to share o nthis topic.

I don't burn dimensional lumber (store wood) myself except for an occasional odd scrap. Not all of it is kiln dried so it may not make a difference. Of course you should never burn treated wood of any time either because of the chemicals used in the process. I'm not sure this is very cost effective either.

I've used Presto Logs (the log version of the bio-brick). They are absolutely dry, but they burn really hot in my stove. If you try them out I'd suggest you do a few at first before loading the firebox up with them to see how they burned. If you can't get your stove hot with bio-bricks/presto logs then there is probably something wrong with how your stove is drafting.

When my wood was wet from the first year I burned I bought a couple pallets of presto logs to get through the winter. You may want to just use that option (or bio-bricks if that's what's in your area). Burning wet wood is always a bad idea and will lead to poor performance.

 

[edthedawg]

Great info / feedback - thanks!! I point my IR therm at the flue (single-wall pipe out the back to the stainless tee, then immediately into the 6" SS flex) and generally the temp reading on the pipe matches the top-center stone temp +/- 25F. Going from a 280-320 surface reading up to ~850 internal flue temp sounds like it'll be... interesting.

Oh btw - I meant those pre-packaged hardware/grocery store firewood bundles - not burning 2x4's ;-)

Gonna pick up a box of those Enviro-Logs (i think that's what they were) from the hardware store, and see how a few of them light off. Then try to find the time to build the big honkin' woodshed...

 

[Risser09]

This is my first year with the Keystone and I love it. I have a basement install and am getting basement temps near 80º (across the basement from the stove). My first floor topped out at 69º last night before bed (outside temps 32º). I haven't even insulated my walls yet, which are 8" block with no other insulating properties attached, aside from being completely underground. My only concern is the stove temp which is only maxing out at around 450º with the cat engaged. I'm burning 90% cherry. Some ash.