Define - "Over-Firing"

Yeah - a fire-engine-red stove & connector pipe are good indicators of overfiring.

You can always do the boiler thing...
Water to air exchanger in the ductwork...
All the hot water you can use...
The last coal appliance you will ever buy...
Several for sale used on the board...
Check out the stoker section...
A boiler is really the way to go...
runs 356 and makes DHW...

CapeCoaler wrote:You can always do the boiler thing...
Water to air exchanger in the ductwork...
All the hot water you can use...
The last coal appliance you will ever buy...
Several for sale used on the board...
Check out the stoker section...
A boiler is really the way to go...
runs 356 and makes DHW...

And the last 9 days of the year?????????????? Sorry CapeCoaler. Just couldn't resist.

Ya not enough sleep in the last 2 weeks...
Well you do have down time for maintenance...

My first year burning, I had an email exchange with Dean at Hitzer on this issue. When I asked how hot the stove could be run, he replied, "If you need more heat, open the ashpan vents wider" , suggesting they had no real sense of what a firm upper limit is. He said that durability of the stove would be affected negatively by running it very hot much of the time. Even "very hot" wasn't quantified more precisely. He also said that, more important than avoiding certain max temps, was to avoid rapid changes in temps. If you burn at high temps, go there slowly/steadily, and come down slowly/steadily.

I thought this info may add to the discussion, and suggests that there really is no firm upper limit. For my setup, as I go above 550*, I don't get much additional house heating (BTU's going up chimney?), so I tend not to go there.

My understanding of "over-firing" is running at too high a temperature where components of the stove are being adversely affected.

The real question that has to be answered is defining how fast the degradation is happening to establish what the temperature for over-firing would be. So really the first thing that would have to be defined is what is the rate of degradation that would be the cut-off where above that the stove is being over-fired and below that it is not being over-fired. I'm sure everyone would agree if you are running at a temperature where parts of the stove are bending or in other ways starting to fail as your running it, that's over-fired. But, for example, lets say you run a stove at a temperature such that in 5 years you have to replace parts. Would that be over-firing? I would think so, but maybe someone else would think that is no problem. So change that to 20 years, is it still over firing? Now how many people think that's over-firing?

All stoves are degrading as they are being used. When does that rate constitute "over-firing"? That is the hard question to answer and really is somewhat arbitrary. Now, add onto that the complexity that different stoves will have different lifetimes depending on how they are made. Do you pick a time frame to failure that denotes over-firing no matter what stove it is?

Before you can figure out a temperature, you have to figure out the time it takes to "hurt" the stove...

dj

Coalfire wrote:Just a question, wouldn't 500 degree stack temp put most stoves at 800-900 degrees? right not I am running 450 with a stack temp of 220. if my stack was at 500 I think my stove would be melting , not really but don't you mean stove temp and not stack temp?
Just wondering, Eric

Where are you taking your stack temperature from? If at an inch above the baro your getting a reading of 220 then that's high and your baro should be readjusted. I just readjusted mine by placing washers on it and my temperature in that spot with my stove at 500* is right around 130*.

IoF

Your chubby should be enough to heat your whole house, what do you have 1200sq ft? I have roughly a 1900sq ft split level house with my stove on the top floor with a fan sucking warm air downstairs I can keep the top floor in the mid 70's and the bottom floor comfortable with a little assistance from my oil heat in the low 70's. Once I move the stove downstairs it should keep the whole house nice and warm without my using oil or wasting electricity.

Really can't overfire a stoker!

I have ran mine over 800 degrees as measued on the front door for hours.

Blower pushes out 165 degree air 24/7 during this time as measured at my registers!

Koker 160

Heat loss in a home is one variable...
Leaky house and insulation levels all contribute to how much heat it takes to maintain temps...
The cottage behind my main house only needs 24,000 btu/hr to maintain 72* at 0* design temps...
We gutted, rebuilt and improved the floor plan of the 600 sq ft cottage...
That results in a monthly gas bill of $50 or less for heat, DHW and cooking...
The renter loves the low utility bills and efficent floor plan...
The main house just shy of 1000 sq ft had a gas bill of almost $500 in the same weather...
It has yet to get the total rebuild but is the same age...
The DSM is rated for 130,000 btu/hr and I will use every BTU it has at 0*...

Wow Cape a 130k BTU's for a 1000sq ft home is a lot of btu's!

It's always much better to fix the house and need less BTU's to heat it then to just buy a much larger stove and spend all that extra money to run it. The more BTU's you need to heat the house in the winter the more air condition you need to cool the house in the summer. It's better to pay up front and fix the major problems then to continue wasting your time and money by always chasing the weather trying to be comfortable in your own home.

See, I don't know if I'd go the boiler route sure have hot water on demand is nice but when one component fails you're down until its repaired. A guy I work with just went through that on his oil fired boiler. He was down for 2 weeks waiting for parts and then after that he just ended up replacing the entire system. Currently, I have a hot water heater that is electric. Last winter it crapped out on me. I still had heat and took me 1/2 hour to replace the hot water heater.

Adamiscold,

I'm sure it would, if my house weren't so drafty. I can maintain 60* - 70* only in the living room @ 500*. The rest of the house sits around 62*.

Adamiscold wrote:

Coalfire wrote:Just a question, wouldn't 500 degree stack temp put most stoves at 800-900 degrees? right not I am running 450 with a stack temp of 220. if my stack was at 500 I think my stove would be melting , not really but don't you mean stove temp and not stack temp?
Just wondering, Eric

Where are you taking your stack temperature from? If at an inch above the baro your getting a reading of 220 then that's high and your baro should be readjusted. I just readjusted mine by placing washers on it and my temperature in that spot with my stove at 500* is right around 130*.

IoF

Your chubby should be enough to heat your whole house, what do you have 1200sq ft? I have roughly a 1900sq ft split level house with my stove on the top floor with a fan sucking warm air downstairs I can keep the top floor in the mid 70's and the bottom floor comfortable with a little assistance from my oil heat in the low 70's. Once I move the stove downstairs it should keep the whole house nice and warm without my using oil or wasting electricity.

That temp is before the baro, and after the mpd.

Coalfire wrote: That temp is before the baro, and after the mpd.

What do you get after the baro? Is you damper usually closed?

Wow Cape a 130k BTU's for a 1000sq ft home is a lot of btu's!

But that is at 0*...
The Cape is fairly moderate in temps most of the winter usually 25* or so...
The rental was the priority to get the cash flow going...
The main house is a project house...
1950's no insulation, sheathing is a gypsum product and so on...
New electric, new title 5, new roof and so on...
The interior saw little money due to all the other necessary work...
Insulation goes in the easy places first...
The ceiling is done with r-36...
The walls need to be ripped out to insulate them so that is next...
My cost per ton on the coal is minimal due to SSM operations and the stove easily maintains the inside temps at 75*...
I might spend $400 on heating the place per year including stove maintence and bin building...
Mining operations may take 15 hours per year...
I might burn 5 ton in a really bad winter and that is heating 1900 sq ft with the basement included...
80% of the infiltration is taken care of, the old single pane windows have storms on them but Andersons are on the list...
Insulating the foundation walls will be done after that...
The house is very comfortable no major drafts but could use some more tightining up...
So on a cost benefit basis I will burn the coal and renovate as needed...
My situation is a bit unique in that my coal cost per ton is almost nill...

Adamiscold wrote:

Coalfire wrote: That temp is before the baro, and after the mpd.

What do you get after the baro? Is you damper usually closed?

I will check on that, never have as that I would think would be an exagerated reading with the air bleed from the baro. That is just my thoughts. I keep the mpd closed 100%. I still pull good draft, I measure my draft below the MPD, so I am seeing what the stove sees. Even with the MPD closed the baro still opens and closes, I have the baro set at -.06". When I close the MPD I can feel more heat out of my circulator tubes instantly , and the coal seems to burn up better.
Have a great day, Eric