Efficiency of a Stoker Stove Vs. a Hand Fired Stove

Until you know the test conditions and what is tested and how, any efficiency claim of superiority is worthless.

Hand fired stoves also match the fire to the load.

I am certain that some stokers are more efficient than other stokers, just as some hand fired are more efficient than others.

i guess i will use some examples when it comes to gas furnaces that come to mind. when i was growing up we had an old, really old gravity gas furnace at the house i grew up at. i know that the gas bill was several hundreds of dollars per month, not cheap to run but it was a simple unit. the house i currently live at has another example of an old POS gas furnace. when we first moved in we heated ONE month with that piece junk. i think the gas bill was $350 for november, it was that bad. both units were simple and reliable, both units also really had really ridiculous operating costs. you can buy a much more modern gas appliance with very significant reductions in fuel costs. you will also pay a significant price for the unit, a unit that likely has a decade or less of service life. when it breaks its likely not going to be able to be user serviceable (it will). my stoker stove is a 2006 and frankly i dont think its even close to the end of its life, its going to need little this and that but nothing major. it really could use new glass (but functions fine the way it is) and at some point something needs to be done with the door handles.

as one of the posters said the complexity of gas furnaces comes with the reduction of stack temperatures. i agree with that assessment, but that's how you get efficiency out of those things. my experience with my keystoker is that its naturally efficient. the stove body can be 450 degrees but the stack temp will be cool enough to touch. the really amazing thing is the black pipe i used has a couple of labels on it from when i bought it, they are on the side of the pipe but not too noticeable. i leave that on there, when someone asks me about the stove i will tell them that pipe is cool enough where those 3 year old labels are still on the pipe.

i formally burned pellets and its a pretty terrible heating option, the cost on a ton of pellets was almost as much as a ton of coal; except a ton of coal has significantly more heat then a ton of pellets.

the $800 i spent on a used keystoker was the best $800 i spent to heat my home. cheap on fuel, easy to service, cheap to repair, much safer then wood.... and while it still makes SOME mess its not nearly as bad as wood. i swear the pellets made more dust.

Window-Stats are the main proof of the serious efficiency fault inherent in all hand fired stoves.

Well, the size of the stove and the air controls have a lot to do with that...but point taken.

lsayre wrote: ↑

Sun. Nov. 05, 2017 9:16 am

Window-Stats are the main proof of the serious efficiency fault inherent in all hand fired stoves.

True enough, but not always.

When coal was king the shoulder months were often handled by kerosene heaters or even radiant gas heaters before firing up the main unit. The hot water tank had a gas fired side arm heater, manually fired.

Window stats use can be avoided by using the oil or gas central heating units most have during this time. Those units are arguably more efficient than any stoker spending most of its time on idle which should cancel out any price advantage of coal.

Having more than one stove also allows tailoring to outside temperature.

And then there is the supreme advantage of the hand fired unit of being able to stand on its own, with no reliance on electricity, and even the ability to burn wood to take the chill off temporarily.

I think it is inaccurate to claim hand-fired stoves have an efficiency advantage over stokers at idle. On any stoker I have ever seen, the quantity of coal kept lit at idle is a tiny fraction of the quantity of coal that would be sitting in the firebox of a hand-fired unit of comparable output capacity. The fact that at idle many stokers are spoon-fed coal by a timer is part of how they burn less coal than a hand-fired, not more.

Mike

Pacowy wrote: ↑

Sun. Nov. 05, 2017 10:07 am

I think it is inaccurate to claim hand-fired stoves have an efficiency advantage over stokers at idle. On any stoker I have ever seen, the quantity of coal kept lit at idle is a tiny fraction of the quantity of coal that would be sitting in the firebox of a hand-fired unit of comparable output capacity. The fact that at idle many stokers are spoon-fed coal by a timer is part of how they burn less coal than a hand-fired, not more.

Mike

If this is in answer to my previous post, then I totally agree, but the claim that hand fired stoves at idle are more efficient than stokers was never made. They are not.

franco b wrote: ↑

Sat. Nov. 04, 2017 8:16 pm

Until you know the test conditions and what is tested and how, any efficiency claim of superiority is worthless.

I only cited the 20% because I believed it to be from a credible source, an internal EFM engineering manual from the 1950's. EFM's engineering from the "golden age" of coal use enjoys a pretty good reputation and I have no basis for believing they lost their minds in making this assessment.

Moreover, this finding is consistent with easily-observed fundamentals, including not only windowstats and the minimal btu's consumed by a stoker at idle, but also things like the capture of btu's from volatiles, the ability of a stoker to be "reloaded" without flooding the appliance with cooling overfire air, and the verification of efficient fuel/air mixes provided by the ash band on underfed and flat grate stokers . I can't say that exactly 20 percent applies to all situations, but as a general proposition it is consistent with my own experiences in running hand-fired and stoker-fired boilers, and hand-fired and stoker-fired stoves. Unless someone presents persuasive evidence or argument to the contrary, it doesn't appear to require further study to accept the general proposition that stokers tend to offer an efficiency advantage.

Mike

franco b wrote: ↑

Sun. Nov. 05, 2017 10:22 am

If this is in answer to my previous post, then I totally agree, but the claim that hand fired stoves at idle are more efficient than stokers was never made. They are not.

I agree that you never stated that hand-firing was more efficient than stoker-firing, and my point would have been clearer if I had referenced your resistance to "any efficiency claim of superiority" for stokers, and your claim that "(H)and fired stoves also match the fire to the load." If, as you state, you now agree with my statement that "the fact that at idle many stokers are spoon-fed coal by a timer is part of how they burn less coal than a hand-fired", does that mean you no longer are asserting general efficiency parity between stoker-firing and hand-firing?

Mike

My 1891 baseburner burns less than 15-20
lbs in 24-30 hrs at idle while producing barrel temps of 150-220 degrees on a 11 sq ft area barrel. What weight of coal would be burned by a typical stoker at idle and would any heat be delivered by the appliance at that setting? If no heat is heat is delivered at idle by a stoker then it's close to 0% efficient.

To me the only measure of efficiency is the amount of BTU per pound of coal VS the BTU that actually gets delivered by the appliance, at ANY setting. And, for any appliance that uses electricity, that "cost" (in BTU) has to be subtracted from the total BTU delivered by the appliance.

Any stoker stove, furnace, boiler inside the home is delivering heat to the structure just like your baseburner at idle.

What's less than 15-20 pounds? Lol is it less than 20? Less than 15? 10 pound per 24 hours?

Lol! Should I ask again?

The simple fact is I don't run the stove when I don't need heat. A stoker would be idling the entire off season when not being called for a DHW call,

Lol Larry reported roughly 12 pounds per day for a week straight.

scalabro wrote: ↑

Sun. Nov. 05, 2017 1:10 pm

My 1891 baseburner burns less than 15-20
lbs in 24-30 hrs at idle while producing barrel temps of 150-220 degrees on a 11 sq ft area barrel.

Is there a way to calculate BTU radiation for those temps with that amount of square footage? That would be interesting to figure.

hotblast1357 wrote: ↑

Sun. Nov. 05, 2017 1:27 pm

Lol Larry reported roughly 12 pounds per day for a week straight.

Idling?