A challenge to anthracite stove makers

Coalfire wrote:So are you saying on my DS box stove I use 40lbs a day unless were at zero or below with blowing wind then it will go to 80lbs that I could use 20-40 lbs a day, cause if I can save that I will keep my eyes open for a glennwood. It takes X amount of btu to heat an area, if it's not going up the chimney it's going in the house.

Eric

Agreed! I've never operated a coal stove with a hopper. I don't understand how a hopper fed stove holding "X" BTU in coal is burns any longer than a batch stove with the same "X" BTU of coal in it's gullet. Coal heat output is controlled by the air fed to the combustion zone - that's the throttle. Efficiency is a matter of air feed, stove surface area and flame path. I've gotten up to 28 hrs on hi-idle with a lot of fire left to start the new load of coal in a reasonable time. Again - I'm not familiar with hopper control burn charistics. Like Coalfire stated: X in , X out or the coal isn't burning.

wsherrick wrote: I know these tests are ancedotal but I have compared notes with other Glenwood owners and their results are very much the same.

And that's the problem, to get accurate comparisons. In the example given with the Chubby the Chubby is a much smaller stove so had to be fired much harder with greater stack loss. If a Chubby model with a blower had been available the results would have been closer.

Once you get that magazine in your Glenwood I think you will agree that there is a significant improvement in feeding hot coal in layers instead of a cold batch.

It is easy to measure the pounds of coal fed in to a stove but difficult to measure the BTU output and each stove should be run at its optimal firing rate. It's too bad that the UL labs. don't publish outputs at specific firing rates while doing their safety tests. You can select a car based on its gas mileage that has been independently tested. It might have no true relation to the real world, but is valid to compare. With stoves,too often, the rating is established by firing the hell out of it. Like selecting a car by how high the numbers are on the speedometer.

VigIIPeaBurner wrote: I don't understand how a hopper fed stove holding "X" BTU in coal is burns any longer than a batch stove with the same "X" BTU of coal in it's gullet.

It will burn a little longer because the hopper will feed a small amount of coal as the batch turns to ash. The real advantage is that hot coal is fed to the fire at shake down time. Some of it will already be coke and recovery time is much faster with very few volatiles going unburnt. A puff back is very unlikely with a hopper. More heat with the same air setting will be produced because more volatiles and CO are burnt. The effect is much like feeding a batch fed stove very frequently with small amounts at a time. This assumes the stove is being fired somewhere in its mid range. In a stove like the Glenwood, the magazine being centrally located, will force the flue gas into closer proximity to the sides of the stove resulting in a small increase in heat exchange as well.

I think that the fire pot form was not a big problem in my Vig ll. Originally, the front part of the fire pot was made from horizontal bars to keep anthracite inside of the stove.
But when opening the front doors, ash and coal parts were falling down from the open space of these bars. But the worst thing was the combustion air by-passing the coal bed to escape from these open bars. It's easier for the air to go throught these bars than from the coal bed. All that changed when I replaced these bars with a 1/2" X 5" X 17" steel plate. At first it was just a test but that plate never got out of the stove. I was almost sure of the result cause I did a lot of testings in placing big 3/4" rope gaskets in the slots of these horizontal bars.
Plus I did a lot of observations on the antique stoves like Glenwood... and realised that the fire pots were closed all around. Yes, they are round but not open in the front. By reducing the right and left sides of the firepot it became more square than rectangular just like a box without the bottom.
Before these modif, the stove had the same internal damper to direct the gasses to the long path, the same thermostat control...in the same house,same anthracite... and the biggest improvement came from the front part changes. Many """modern""" stoves have wide fire chambers and retaining horizontal bars and I think it's a poor desing ,in my head.

I can accept the argument about the magazine feed versus dumping fresh coal in. That is easily explained via the nature of combustion itself. Hot fuel ignites quicker than large mass of fuel that must absorb enough heat to generate volatile gas and then get hot enough to ignite. Now I want to inquire about the nature of the forced cold air brought through the fire by a blower. I can buy the argument that a blower in the stove is a way to compensate for an inadequate amount radiating surface area but is it true or not that robbing the combustion chamber of that much heat destroys combustion efficiency. You know that to properly burn hydrocarbons and CO that you must maintain a very high temperature in the fire box or those gasses and their heat is lost up the stack. You also have to have enough air as well. A stove like the Glenwood which has 27 square feet of radiating surface plus a large combustion chamber to maximize combustion efficiency is more efficient overall than a smaller stove with a blower. I believe that is why I can get such a wide temperature range on it and still maintain incredible efficiencies. The hottest I have run the stove is around 750 degrees because I wanted to figure out where the stove maxed out in it's ability to efficiently radiate heat before it had to start wasting heat up the stack. At 750 degrees the stack temp still remained at 115 degrees. So I don't really know where that point is on the Glenwood. All of that heat came blasting out into the house. At that high temperature there was enough mass and radiating surface to extract that heat. A blower, like you say can raise the thermal efficiency of a small stove but to the same extent that is shown here without again lowering combustion efficiency by quite a margin. Yes? No?

wsherrick wrote:I don't know how your house is set up. In the coldest sub zero weather I never burn more than 40 or 50 pounds of coal a day in the Glenwood. Others may have different results. I am reporting the results I have obtained with it and compared it to all the other stoves I have ever had or been around in a half century of heating this way. I don't know how much surface area your DS has, but; the Glenwood has over 27 square feet of radiating surface area to work with.

My stove has 30 square feet of radiating surface. So what do we do now? It takes X amount of btu to heat an area if the heat doesn't go up the chimney it is going in the house. You can't get around that it is a simple fact. So I doubt there is anyway a glennwood would be more efficient. but here is the flip side maybe the DS would be more efficient for you



Eric

While I hate to step into a stove arm wrestling match, I will add that if the btu content of the coal, pounds burned per hour, draft, and temperature of the room and combustion air are held constant...stack temperature should be a good indicator of efficiency. The square feet of the house doesn't mean much in my opinion, since the heat loss can vary considerably depending on wind exposure, solar gain, etc etc.

Coalfire wrote:

wsherrick wrote:I don't know how your house is set up. In the coldest sub zero weather I never burn more than 40 or 50 pounds of coal a day in the Glenwood. Others may have different results. I am reporting the results I have obtained with it and compared it to all the other stoves I have ever had or been around in a half century of heating this way. I don't know how much surface area your DS has, but; the Glenwood has over 27 square feet of radiating surface area to work with.

My stove has 30 square feet of radiating surface. So what do we do now? It takes X amount of btu to heat an area if the heat doesn't go up the chimney it is going in the house. You can't get around that it is a simple fact. So I doubt there is anyway a glennwood would be more efficient. but here is the flip side maybe the DS would be more efficient for you



Eric

Nice try but no cigar. What is this X Btu in the house or up the chimney stuff. You need to explain that to me so that I can understand what you are saying. How much coal does your stove burn over a set time to produce how much heat, what is your stack temp, what is the stove temp and the difference between the two??? How efficient is your stove at not only radiating the heat produced, but; how efficient is the combustion the fuel in the stove? How much potential heat is lost in unburned gasses going up the chimney? All of these questions are relevant to how efficient any heat producing device is. How much work is obtained out of the total potential energy available? If your stove has 30 square feet of radiant area that's a pretty big box you got there. The amount of BTU's to heat any given area depends on condition of the area. Heat loss, air infiltration and other factors depend on how many BTU's to heat an area. There's also some one's comfort level. That is also dependant on how warm some one likes an area to be. Can your stove heat a two story house and basement and burn 50 pounds of coal a day in sub zero weather to do it? If your stove can do that fine, but; I bet it can't. I seems like you are taking this quite personally and you don't need to. Maybe you should trade the box for what's behind curtain number 3.

franco b wrote:

wsherrick wrote: I know these tests are ancedotal but I have compared notes with other Glenwood owners and their results are very much the same.

And that's the problem, to get accurate comparisons. In the example given with the Chubby the Chubby is a much smaller stove so had to be fired much harder with greater stack loss. If a Chubby model with a blower had been available the results would have been closer.

Once you get that magazine in your Glenwood I think you will agree that there is a significant improvement in feeding hot coal in layers instead of a cold batch.

It is easy to measure the pounds of coal fed in to a stove but difficult to measure the BTU output and each stove should be run at its optimal firing rate. It's too bad that the UL labs. don't publish outputs at specific firing rates while doing their safety tests. You can select a car based on its gas mileage that has been independently tested. It might have no true relation to the real world, but is valid to compare. With stoves,too often, the rating is established by firing the hell out of it. Like selecting a car by how high the numbers are on the speedometer.

Outside of a lab how does one determine the optimal range of firing? You have to take both thermal and combustion efficiency into account. Franco I know you are well aware of the paradox there. Most times the increase in one decreases the other.

Like Franco said, I also would like to have lab data on coal stoves and comparisons. But I know an other fact: when I bought a V.C. Defiant wood stove rated from EPA at 0.85 Gr/hr, I was sure to have a very clean burning stove. But the reality got an other data. There was almost always smoke at the top of the chimney. Did try all I could and even install a watching ouside camera aiming to the chimney's cap to see what was happening on the small monitor. Nothing to do and sold it after only 1.5 year of observation.
All that to say that, now I make my own ""LAB"" testings. If I make modifs. on the stove and get the same or more heat with the same house, same room temp., same chimney, same anthracite batche, same wife and all you want, and with less problem, and less anthracite I don't need more. Every days I write : the Hour (8 AM, 8 PM), outside Temp., inside Temp., stove's Temp., anthracite pounds , wind or not, snowing... Without even knowing it, the modifs I made on my stove are a sort of copy of the well working Base Burners...
If stove makers are arrived at their's peak performances, someone is sleeping somewhere and I invite them to come here for a full winter in my real lab.
A good proof of all the problem is that: we still need to compare the 100 Yrs old stoves to the ""new"" ones.

Just want to throw this in here as an example. I am on my 3rd year heating a ranch home which includes the full basement and full first floor. A little over 2500 sq. ft. I am burning a newer box style Buck Model 24 Coal Stove and burning 36 lbs. to 48 lbs. of coal per day. 36 lbs. on normal winter temps. and 48 lbs. on those really cold frigid days. The baseburners are really nice stoves and do a great job heating but there are also some nice and efficient modern stoves on the market today. I burned a Warm Morning 523-R for 29years and then swiched to the Buck Model 24 Coal Stove I cut my coal consumption in half and the same or better heat output. Go's to show the difference in stoves. Should have got the Buck sooner

One thing is sure in my head about stove conception is that a round fire pot with a good shaking grate systm. is certainly the best of all to avoid ash build-up. Reducing my combustion chamber and with modifs on the grates improved a lot for ash build-up but a round fire pot has no corner and no horizontal parts to stack ashes.
Simpler and better.
Make a new performant AND NICE anthracite stove would cost a lot but Mass hearth, enameled cast iron stoves, pellet stoves...Geo systm. cost also a lot and a lot are sold each years. None can compared to anthracite burning so where is the problem if not from new stove makers?

At least we have at lot more fun with our stuff than those who just turn the thermostat and pay the bill.

wsherrick wrote:At least we have at lot more fun with our stuff than those who just turn the thermostat and pay the bill.

Agreed.


In answer to your previous query about blowers; yes the blower will lower combustion chamber temperature if the double skin is over that portion of the stove. That's a no no in my book. Most only effect the back and top. They don't blow air through the fire. We are not talking about a primary forced air blower such as used in a stoker.

Got another stove today. The mid size Franco Belge. Now I have all three sizes. Someone decided to improve it by drilling a series of holes in the front edge of the fire basket, so now the air can bypass the coal. I suspect this is the reason it obviously has never burned much coal. Easy to undo.

wsherrick wrote:

Coalfire wrote:

wsherrick wrote:I don't know how your house is set up. In the coldest sub zero weather I never burn more than 40 or 50 pounds of coal a day in the Glenwood. Others may have different results. I am reporting the results I have obtained with it and compared it to all the other stoves I have ever had or been around in a half century of heating this way. I don't know how much surface area your DS has, but; the Glenwood has over 27 square feet of radiating surface area to work with.

My stove has 30 square feet of radiating surface. So what do we do now? It takes X amount of btu to heat an area if the heat doesn't go up the chimney it is going in the house. You can't get around that it is a simple fact. So I doubt there is anyway a glennwood would be more efficient. but here is the flip side maybe the DS would be more efficient for you



Eric

Nice try but no cigar. What is this X Btu in the house or up the chimney stuff. You need to explain that to me so that I can understand what you are saying. How much coal does your stove burn over a set time to produce how much heat, what is your stack temp, what is the stove temp and the difference between the two??? How efficient is your stove at not only radiating the heat produced, but; how efficient is the combustion the fuel in the stove? How much potential heat is lost in unburned gasses going up the chimney? All of these questions are relevant to how efficient any heat producing device is. How much work is obtained out of the total potential energy available? If your stove has 30 square feet of radiant area that's a pretty big box you got there. The amount of BTU's to heat any given area depends on condition of the area. Heat loss, air infiltration and other factors depend on how many BTU's to heat an area. There's also some one's comfort level. That is also dependant on how warm some one likes an area to be. Can your stove heat a two story house and basement and burn 50 pounds of coal a day in sub zero weather to do it? If your stove can do that fine, but; I bet it can't. I seems like you are taking this quite personally and you don't need to. Maybe you should trade the box for what's behind curtain number 3.

Nothing personal and I'm not going to try and argue it cause your mind is made up and that is how it is. I don't understand this two story house and basement stuff, see you will have to explain that to me size and temp that your are trying to achieve with your 50lbs of coal. Like someone said are you heating a 4000sqft corn crib or a 1500sqft house? You said 50lbs of coal 50x13000= 650,000btu per day if you get every last ounce out of the coal 650000/24= 27,083btu/hr average. so your are saying I could put a 30K btu space heater in the basement of a two story house and heat it comfortably on a sub zero day?

Oh by the way what is behind curtain number 3? I hope it is one of those electric amish mirical heaters, I heard that whole amish communities were working there fingers to the bone so every household could have 2. They run for pennies a day you know, someone on the infomercial said there furnace went out and they pulled out there mirical heater and it saved the day