Btus Vary So Much. How Do I Tell What We Need?

Hi, everyone!

This is my first post on the coal forum after lurking around for a few days. My hubby and I were set on a pellet stove until a guy at work told him that you can direct vent some coal stoves. Now we're leaning heavily toward coal (don't worry--I know what you guys think about pellets and I'm starting to agree the more people I talk to--the wet pellet issue, inconsistency in quality, lower BTUs, etc.).

I'm writing to ask for a bit of guidance about BTUs on stoker stoves. We live in Down East Maine where it's COLD like I've never experienced before. Spent more than $3,000 this winter on fuel oil. With current prices, we'd be at $4,500 next winter. Not an option--we're already broke from this winter! We're in a 2,144 sq. ft. Victorian two story built in 1890. It's got newish windows but has high ceilings, is pretty drafty, and there's almost no insulation (besides what we added in the attic). So I think we need a fairly hefty stove. We've got forced air, so can't do the boiler I see you guys recommending. I know at least one Leisure Line will tap into an air furnace but I don't like the power vent idea AND we don't have an extra, lined chimney to add the coal furnace to anyway. So it's a stoker stove for us.

After months of digging around, I'm pretty sold on Harman quality (even though I saw the complaints about getting in touch with them, seems like they make a great stove). We really like the DVC-500 Direct Vent stove. Kept our house at 64 this past winter (60 at night). Brrr--thank God for down comforters!

So here's my question finally (is there a word limit on these things?): the Harman DVC-500 says 75,000 BTUs and it will heat up to 2,200 sq. ft. BUT Leisure Line stoves go up to 90,000 BTUs and higher--and a local-ish dealer told me the Pioneer LE Back Vent is only good for 1,800 sq. ft. I thought Harman was pretty careful about their estimates. So is their stove just good enough that it can heat more house with fewer BTUs? Or is Leisure Line underselling themselves or making a lower quality stove? (unusual--Quadra Fire is busy saying 45,000 BTUs of pellets can heat 4,200 sq. ft--overselling IMVHO) Why such a huge discrepancy between the BTUs and what they say the stoves will heat?

Because we live in the middle of nowhere, we've got few options for dealers. Can get to Harmans here in town (a small miracle) or Leisure Line/Reading through a guy 2+ hours away but I think that's it. I know this is all approximate--I just wanted to know what you guys think about a 75,000 BTU direct vent coal stove for our application. Sound OK?

Oh yeah--I'm also a bit worried about getting our hands on rice coal. Got one guy willing to deliver here but what if he changes his mind in a few years? Do you all see anthracite coal growing enough in popularity (especially way up here in Maine) that it's a safe way to go? We can get pellets from six people right here in town but NO coal. Think that'll change since it seems to be catching on again?

THANK YOU for reading my ridiculously long post, and for any info you can give me!
StinainMaine

Welcome to the forum. Have you checked the local feed and lumber stores in your are? I am in mid coast Maine and get almost all of my coal from Agway and a farm supply store. In Maine (at least around me) Agway, Aubachon and several others carry coal all winter and some all year round. Rice coal is harder to find in Maine than pea and nut, so if you can try to get a stove that will burn one of those. Call around to all of the lumber yards and hardwar stores in your area and ask if and what they carry on a regular basis. Some of them will also order coal for you, if they don't have what you want. I heat my 3000 sq ft house here for about 5 tons a year with a hand fired stove. Good luck and stick with the coal idea. There is a reason you see so many used pellet stoves for sale.

Thanks, coal-cooker! I hadn't thought about asking EBS or Johnson's if they'd order it for us. I'll have to call around a bit. It's so much more expensive up here than in PA. We're looking at $339/ton bagged and delivered--eek!--but it's better than oil or pellets, me thinks!

Do you have any sense of whether or not more people are begining to move to coal up here in Maine? It's so bloody cold, seems like it's a smarter/warmer heat for this climate.

Re: the pea and nut coal, we have to direct vent, and I've not seen a non-rice direct vent coal stove. Thanks for mentioning your usage. We're guessing about 4 tons but we can't run out, given the delivery distance, so that's a whole 'nother project(once we get the stove purchased)--figuring how the heck many tons of coal we'll need.

Hello StinainMaine..welcome to the forum.. First.. you can use a boiler to provide heat for a forced air heating system.. It's a very popular method.. The trick is using a water-to-air heat exchanger.. it looks about like a A/C coil installed in the ductwork above the furnace.. AND you can use the boiler's water to heat your domestic hot water [unlimited hot water ! ]. However, a good chimney is a must,, or at the very least a powervent.

The BTU ratings often are fairly accurate, based on how much coal the stoker can push and burn per hour.. multiplied by the BTU of the coal per pound. This is input BTU.. output BTU is what you feel in the room our house, the difference is what goes up the chimney... an efficient stove body design, with a proper barometric damper will make the stove output BTU much higher.

If you plan on using a stove for all your heat, not just a suplement to your existing heat, you must plan on heating for the very cold weather.. I'd get a LL Hyfire unit... they are very capable, can be purchased with a 'bonnet' that hooks into forced air ductwork.. Harmans are good stoves, but I would not go with the DVC,, not for all your heat... I'd get a Harman Magnum stoker... a real workhorse, and built like a tank,, but pretty pricey,, if I were buying new, I'd go LL Hyfire with the coaltrol controler.. set it and forget it..

Hope this helps.. Keep reading, there is a wealth of info on the forum..

Greg L

The stove LL. makes that hooks into your air plenum is called either the Hyfire I or Hyfire II 140,000 and 180,000 BTU input respectively. For your climate I would think the dvc would not be enough and contray to Harman dealers belief the power vent type LL. uses (SWG) is the best type IMO. because it incorporates a barometric damper to control the draft and it keeps the exhaust pipe under negative pressure which doesn't require the joints of the pipe to be sealed so you can take it apart to clean it. I had Harman pellet stove and they don't though near the heat of my coal stove. Another option would be to power vent the oil furnace and put the coal stove in the chimney considering the oil burner won't be used that much. Also the coal -trol that comes with the Hyfire's will do a better job of regulating the heat in the house compared to the Harman contols.

I'd go with the boiler method for several reasons. First it's the most effiecient. Second, you get virtually free domestic hot water as well. Use your chimney for the coal boiler and if you find you still need the oil boiler, power vent it. You likely won't need it.
Here's a picture of the water to air heat exchanger. It's important that it be sized adequatley.

You also mentioned that your house is drafty. First order of business is to tighten it up. You said the windows are newish? Find where the drafts are coming from and seal them out. That's worth alot of BTU's. Coal is a smart move but conserving the heat you make is just as important.

There are several of us from Maine on the forum. Freddy is up by Bangor and Rberg is down by me. I am just outside Augusta. Downeast Coal sells Reading, but everyone will tell you to stay away from it. There are not many dealers selling rice coal around here, so you may have to travel abit to get it. Check with your local farm supply dealers and see if they will order you what ever size you need. Blashak is about is good as you are going to get locally. As more folks start burning coal, I think you will see more dealers carrying it.

Welcome to the forum! Good people, good knowledge freely shared.
$340 a ton is about the going rate for bagged coal around here. At that price is it less than half the cost of oil (if oil was $3.50). I'm going ot buy a giant truck load direct from Superior Coal in PA. It will be a 4 or 5 year supply, but it brings the price down to about $200 a ton. There are a few places in Maine that will bring you coal or see to it that it's delivered. Downeast Coal in Gouldsboro is close to you. Pelletier Flowers in Arrostook county might be able to help you. Paris Farm in Newport is another. One way or another you can get coal, and yes, I think in the next few yrs you will see someone stocking a pile.

StinaInMaine wrote: So here's my question finally (is there a word limit on these things?): the Harman DVC-500 says 75,000 BTUs and it will heat up to 2,200 sq. ft. BUT Leisure Line stoves go up to 90,000 BTUs and higher--and a local-ish dealer told me the Pioneer LE Back Vent is only good for 1,800 sq. ft. I thought Harman was pretty careful about their estimates. So is their stove just good enough that it can heat more house with fewer BTUs? Or is Leisure Line underselling themselves or making a lower quality stove? (unusual--Quadra Fire is busy saying 45,000 BTUs of pellets can heat 4,200 sq. ft--overselling IMVHO) Why such a huge discrepancy between the BTUs and what they say the stoves will heat?

The discrepancies between the BTU output of stoves and the sq footage they heat depends on each house. A newer 2100 sq foot home with good insulation will take less BTU's to heat it compared to a 2100 sq foot home built in 1890 thats drafty.

I heat my 1887 Victorian with a boiler hooked to the forced air, it works very well and provides free hot water in the winter, cheap hw in the summer. I'd get an EFM 520 and hook that into your chimney, it will heat your house easily and it's all automatic. If coal is really ~$350 per ton I would think that an outdoor wood boiler might be a better option.

An outdoor wood boiler is only worthwhile if you have a strong back and access to free or very cheap wood. I have a friend that installed one. It works well, but uses far more wood than it might. It's also a lot of labor. If you are buying cordwood at street price, $350 a ton for coal is about the same price.

Drafty old house?
Forced hot air?
Tired of the heating bills?

BOILER, BOILER, BOILER!

Priceless comfort at a reasonable cost.

Several people above have recommended a boiler with a heat exchanger in the existing air plenum. It's a great idea because it solves the problem of how to DISTRIBUTE all that heat you are making. One way to estimate BTUs required is, calculate how many BTUs you used in previous years to heat with oil (gallons times 140,000 times overall efficiency). Then apply similar formulas to coal and you should be able to come up with tons. As far as how big (maximum output) of a coal boiler, do the above calculations for full-season BTUs needed, divide by number of hours in the heating season, then (arbitrarily) multiply by about 3 because on cold days you will need far more BTU per hour than on average days. Then ask your oil furnace guy how many BTU per hour your oil system can deliver, and use that as a cross-check on your own calculations. Advertisers who quote square-foot heating capacity are ridiculous because houses differ so much from one another.

LeisureLine stoves published BTU's are input BTU's,Harmon's are output BTU's,Harmon literature states 104,000 to 108,000 input to get 85,000 output,I forget which stove this applied to,that's about a 20 percent loss,assuming that loss to be an industry average 80% efficiency is in line with oil burners.90,000 input for LLpioneer would then yield 72,000 output,similar to Harmon's dvc stove.The details and confusion are usually in the fine print. Rich

WOW--thanks, guys for the terrific info! My hubby read it, too, and we're going to call the guy in Gouldsboro about the Hyfire (I or II) on a power vent. That way we've got our oil furnace as a backup if we go to Florida in February We hadn't considered the furnace unit b/c we didn't realize you can power vent it. This way we'll have warm air blowing through the whole house in the vents instead of hoping it makes it upstairs. Sounds much warmer than the stove on the first floor!

We don't have a lined chimney, so doesnt that mean we couldn't do the boiler? Don't those require a lined chimney instead of a power vent? Also, thanks for the info about how to figure BTUs--I'm writing it down so we can do the math later.

Nice to "meet" you guys from Maine! Everyone here has been so friendly since we moved here last March!