Tech question - square footage stats - how to 'read'

[REF1]

After looking at hundreds of stoves the last few days I am settling into a Woodstock, either Fireview or Keystone. Any owner testimonies on how both work in their square footage dwelling would be greatly appreciated. My wife really likes the Homestead, but I am having reservations about Hearthstone. If they produce a "Lemon" we'll be the ones who get it. Returning a stove is obviously not like returning a toaster.

I haven't burned wood in 8 years and used to be a fanatic. I've had Elmiras, Hearthstone, and Elms. Had more literature than kindling sticks. Living in Maine made it mandatory I knew what I was getting into. The 36" Cat Elm was a wonderful stove. Have left Maine and will not face as near a severe winter in VA, but it still drops way down at night in the mountains.

Anyway ... square footage stats for all stoves.

When the company advertises their stove as X number - X number of square feet, exactly how should that be interpreted. I wrote Woodstock about this and hope to receive a reply today, which I will post here if it helps anyone out.

Example - The Woodstock Fireview. 900-1600 sq'. I have seen posts around here that people are heating well over 2K with this unit, as well as other stoves with manufacturers numbers being exceeded. How does this work?

Does 900 sq' = January/February cold penetration, and 1600 sq' = Oct/Nov, Mar/April cold penetration?

Our home is 1300 sq ' for both floors, and I'm adding on another 350 sq'. I'm not going to count on the stove pushing heat back to that location but it would be nice. Kitchen, Living, Dining open floor plan. Bedroom, bath and laundry off a hallway. I'm taking out 8 feet of the hallway wall to open things up into a converted family room. The hearth is somewhat centrally located. The stairs run up opposite the hearth and heat should rise okay to the upstairs.

My concern is the major one for purchasers. I do not want to roast myself out, nor shiver when the temp hits zero. We are quite comfortable at 65-68 in winter. Over 70 and we both feel uncomfortably warm. Owning that 700 pound beast of a Hearthstone was like riding a bull. That 18" of skin that moves around is a no-man's land. It worked fine in January in a 3000 sq' house, but killed us in the Spring when things stayed cold at night, but began warming up during the day. The Elm was so much easier to control.

I confess I am not a fan of "television" stoves. 85% of stoves on the market (mostly steel) remind me of a TV on a stand. Cast iron has design variations, and I just like the natural look of the soapstone. But I know soapstone is deceptive in the kind of heat it can throw off, regardless of how "smooth." Being familiar with Cats, I have no problem with using them. And I would rather use one.

Spec-wise, it would seem the Keystone, at 800-1300' feet would be the stove to get UNLESS that 800' reflects Jan/Feb temps. I am looking to do 24/7 burning as primary heat. The house does have electric baseboards and in an emergency I can click them on to supplement, but I'd rather not. If power goes (as it does in the mountains) the stove has to carry the heating burden.

So, if anyone has any info on how stoves are rated for sq ' heating, as well as being an owner of a Keystone, I would greatly appreciate the info.

Thanks.

 

[branchburner]

I don't know how they are arrived at, but I would use sq ft ratings only as very basic guide. Same for max BTU output. These numbers reflect the firebox size, and fuel capacity is the key to heating capacity. As you noted, there is a great variation in actual mileage depending on climate, insulation, room layout, etc.

I think either of the Woodstocks is fine for you. They are close enough in size that it is not going to be a matter of one cooking you out or one not being enough stove. I assume this forum is filled with Fireview owners because they like its look and because it has a slightly larger firebox. Personally I would want an even bigger firebox, but between the two I would take the Keystone because I think it looks better, has more glass and has an ashpan.

Does anyone else find it strange that all the Woodstock stove are the same basic size? Where's the papa bear?

 

[Slow1]

The Sqft radings on stoves are at best an estimate by the companies and at worst (in the case of some manufacturers) a marketing gimmick. There simply isn't an industry standard way of calculating these so they really can't be compared from one brand to another.

With that said, I believe that the numbers from the folks at Woodstock are very conservative. When they say that the Fireview can heat 1600, I am convinced that they really do believe it can heat most 1600sqft houses well enough to insure their customer's satisfaction.

In making my decision to go with this stove I looked at the BTU ratings, both the peak and the "EPA range" provided. For the FV both of these were considerably (20-35%?) higher than the stove I was replacing. I knew that the old stove could just about heat my 2200+/-? well enough so I figured even though the sqft rating was lower for the FV it would do at least as well. Now we still haven't actually hit a real cold spell, but so far I'm finding it has not trouble at all - and I'm running it very cool - today was the first time I actually kept it going for more than 24hrs, but it is a very low burn.

Which brings the next point - you mentioned you are comfortable with cat stoves so you already know this, but you shouldn't be worried too much about being roasted. Yes, I have overheated the house (up to 75 which is more than we like) but it was my own fault for loading it too much - I learned and haven't done it again. I think once you learn the stove you will learn to moderate your loads and cook it nice and low/slow as needed.

So... back to your question - If you have 1300 + 350 for a total of 1650 then the FV should easily be able to heat the whole space (assuming the layout is set well enough to move the air around). I also bet you could burn it low and slow enough to avoid being baked - but that (like any stove) will depend on your ability to move the air around the house.

 

[Backwoods Savage]

Welcome to the forum REF1.

With your setup, I surely would not want a stove with a smaller firebox than is in the Fireview. On whether it would heat your home or not depends upon the insulation of the home and the layout.

I highly doubt a Fireview would roast you out. We have a relatively small room ours is in but rarely does it get to warm in there. The "soft heat" you hear about is true or at least this is the first time for us to experience it and we love it. In addition to that, we learned that it is best to have a small fan (we put one in our hallway) to blow (on low speed) cool air into the stove room. That, in effect also gets the warmer air into the cooler rooms. This certainly would be a big move for you because of not liking things too warm.

On the whole, I'd say the Fireview would be your best bet. You can also choose the colors of that stove and I'm sure you already know about the fantastic money-back guarantee from Woodstock.


Rather than writing to the company, I'd suggest calling them. They will answer all your questions over the phone and of all the calls I made there (many) I never experienced a high pressure sales person. But I did experience some well-informed people who know their stoves. A couple times I did get someone who did not have an answer to my question...but quickly transferred me to someone who could answer it.


Good luck to you.

 

[Wet1]

Agreed, you'll want the larger Fireview.

 

[Danno77]

I'd do these two simple things and then call it a day, no point in OVERTHINKING (lol, but everyone here does it anyway, myself included)
1. Find a good BTU need calculator, they are everywhere, do a google search or look at some HVAC sites
2. Find the Calculator on Hearth.com that lists firebox size and burn times (there are BTUs listed for various burn times)

Now, take the firebox size the manufacturer gives you and do your calculations on 75% of it's size. make sure you are specifying what kind of stove it is, and also look at the kind of wood you'll be burning.

find the size on that second calculator that corresponds with your BTU needs, but look at the 6 hour burns for what you think you need, if you look only at the 4hr or the 10hr BTU rates then you are either gonna be running your stove at max and having to reload often, or running your stove at minimum and having poor draft and cooler flue temps.


#1) https://www.hearth.com/econtent/index.php/articles/how_much_heat_does_that_room_need
#2) https://www.hearth.com/econtent/index.php/articles/burn_time_calculator

 

[REF1]

Yeah, in looking at the overall mass of the stoves, they are so heavy one might figure either will throw off plenty of heat once brought to steady burns. There is something odd about the difference in 35 pounds of stove and 10K BTUs. I do like the Keystone window better, and yes, the ash pan is a big plus over the FV. I suppose the FV has too low a profile to get a decent ash pan on it. That also means a solid firebox floor, which may account for some extra BTUs.

Back to my original question. Most people want to know if a stove will heat their space. So, if the homeowner has 2K feet to heat they look for that in spec info. I am wondering what the purpose is of stating a stove will heat a minimum space? I have no doubt both stoves will adequately heat my house, just based on their mass. And, indeed, cat control is a parameter that makes a difference in the whole operation. But with all stoves generally advertised with low to high square foot ranges, I have to believe cold penetration has something to do with those numbers. If a stove is running efficiently and can heat 1600', it would have to run inefficiently to only heat 900'. Is that logical?

 

[REF1]

Man, this site has a little of everything. I'll have to check this out. Thanks.

 

[Wet1]

I haven't looked into the details of these two models, but I think you might be misguided or over-thinking the mass thing (cleaver marketing tends to do this). Heat stored in 35# of soap stone (or steel for that matter) wont heat your home for very long at all, we're talking a few minutes here. Ash pans are sometimes more hassle than their worth and the hole in the bottom is generally covered with firebrick. The FV has a larger box, so it can provide more BTU, the ash pan hole has nothing to do with it. The mass of the stoves has little to do with their ability to heat your house, a barrel stove will do that and it has hardly any mass... it just wont retain heat long after the fire dies down. And no, you can heat less sq ft with a smaller fire and the fire dampened down, or more sq ft with a larger fire, but you have to reload more frequently.

Like I mentioned, the FV would be a better fit for you, unless you prefer to fill the stove more frequently.

 

[REF1]

The 35# was in reference to the difference between the FV and Key, and how there is a 10K BTU difference, which didn't seem possible for just that amount of stone or stove material in weight.

I wasn't aware the FV had any ash pan grates. So, the size of the firebox is that main element of BTU total?

While mass means little to heat potential in throw off, it does mean something for duration of usable heat, which is part of the whole process, and also figures in to reloading necessity, right? There is an obvious reason soapstone does what it does, as well as it does it. If you just want a quick fire to take the chill off in the Fall or Spring, a steel stove is great. But just getting the chill off with a large soapstone would be trickier.

In using the calculators provided, and others, it would appear either stove will do well in the house. But, as pyro states, the smaller firebox will logically need refilling more frequently.

 

[Wet1]

The 35# was in reference to the difference between the FV and Key, and how there is a 10K BTU difference, which didn't seem possible for just that amount of stone or stove material in weight.

I wasn't aware the FV had any ash pan grates. So, the size of the firebox is that main element of BTU total?

While mass means little to heat potential in throw off, it does mean something for duration of usable heat, which is part of the whole process, and also figures in to reloading necessity, right? There is an obvious reason soapstone does what it does, as well as it does it. If you just want a quick fire to take the chill off in the Fall or Spring, a steel stove is great. But just getting the chill off with a large soapstone would be trickier.

In using the calculators provided, and others, it would appear either stove will do well in the house. But, as pyro states, the smaller firebox will logically need refilling more frequently.

Don't assume the weight has much, if anything, to do with the BTU range of the stove. Like I stated above, a barrel stove might put out more btu, but it has minimal mass.

Firebox size is generally a large (if not the largest) contributor to btu, and certainly so if all other things are equal. More fuel equals more heat.

More mass will mean more stored energy, yes. BUT, the difference of say 35# is almost negligible in terms of real world stored energy. It's also true that soapstone stores heat longer than steel (and will likewise take longer to heat up), but the difference with all other things being equal is again the difference of a few minutes. There's some truth in the marketing/advantages of soapstone, but if you crunch the numbers, that 15 minutes of retained heat isn't going to amount to much. Be careful not to assume a soapstone stove will function like some 10+ ton masonry heater... they aren't much different at all than a steel stove in heat retention. Again, we are talking a few minutes (~15 minutes) for say a 450# stove, certainly not hours.

And yes, you are correct that both stoves will heat your house, the larger one just wont have to be refilled as frequently. This is more important/obvious during the coldest weather.

 

[branchburner]

Even though the max BTU rating is close and the stoves similar in mass, the Fireview firebox is nearly 50% larger then the Keystone (about 2.2 vs 1.5 cu ft). It's a much bigger difference than I remembered!

I believe you are correct, the space devoted to ash pan in the Keystone is devoted to firebox in the Fireview. I am surprised there isn't a greater difference in Woodstock's estimated burn times and sq ft heating ranges for the two stoves.

 

[REF1]

I used to have notebooks of info on all this. Is there a page here at hearth.com, or a site elsewhere that addresses actual performance numbers of steel vs. iron vs soapstone heat retention and actual appreciative, usable heat?

Having had steel, soapstone, and steel/cast iron I definitely saw /felt differences in appreciable heat once the fire went down. Of course, each stove was not the same weight or mass either. All were big, but obviously a 700 pound soapstone is not a 450 pound steel. That's why I would like to see some numbers crunched on paper.

 

[Backwoods Savage]

Not that I am aware of.

The simple reason I feel you would be better off with the Fireview is burn time. The difference in the size of the firebox means a lot. As for me, I surely would not want a firebox any smaller than the Fireview. I'd much rather have a larger firebox. As it is, you can not put too large of a piece (or 2 or 3) of wood in this stove and that is how you get longer burns is to have larger pieces of wood.

With a smaller firebox, you would be reduced to very small splits. That will give you a quick fire but not a very long fire. I am not certain if you could even get an 8 hour burn with the Keystone. I think those are made for the casual burner; hence, the larger window. But don't discount the window size of the Fireview either.

If at all possible, why not try to get to the Woodstock plant for a tour? That would be the absolute best and you should not be that far away. You could even pick out some possible colors while you are there. It is a toll free call to talk to them.

 

[SolarAndWood]

Dennis, what do you consider a larger piece of wood and how many years has it been sitting in your stack?

 

[Backwoods Savage]

I consider a larger piece of wood to be 6" or more for a round or split. The wood we burn this year is 6 and 7 years in the stack.

 

[SolarAndWood]

Other than can't fit through the loading door, is there too big if it is bone dry?

 

[Backwoods Savage]

It all depends upon the size of the firebox. Remember that to have a good fire one must have at least 3 pieces of wood; 4 is better yet.

 

[SolarAndWood]

Thanks Dennis. I'm a couple years ahead now and thinking about those overnighters a few years out. 8x8s in a 4.3 cu ft firebox seem about right?