Pounds of Anthracite Burned Per Hour Vs. Output BTUH

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sat. Mar. 19, 2016 7:28 pm

Pounds of anthracite burned per hour vs. output BTUH. (BTUH = BTU's per hour)

1 = 8,575
2 = 17,150
3 = 25.725
4 = 34,300
5 = 42,875
6 = 51,450
7 = 60,025
8 = 68,600
9 = 77,175
10 = 85,750
11 = 94,325
12 = 102,900
13 = 111,475
14 = 120,050
15 = 128,625

The highest I've ever gotten (or more properly, needed to get to in order to heat our house on the coldest day I've ever seen) is to about 4.5 lbs. per hour burned. The AHS S130 should however be capable of eating about 11 lbs. per hour.


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StokerDon
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Stoker Coal Boiler: BairMatic BMC-500 with Van Wert VA400 Stoker, Gentleman Janitor GJ-671/EFM S-15 stoker, Van Wert VA-600
Hand Fed Coal Furnace: Harman SF3500
Coal Size/Type: Rice and Chestnut
Other Heating: Noth'in but COAL! Well, Maybe a little tiny bit of wood
Location: PA, Southern York County!

Post Sat. Mar. 19, 2016 8:30 pm

Larry,

Is this net boiler output? Or gross input?

-Don

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sat. Mar. 19, 2016 8:40 pm

StokerDon wrote:Larry,

Is this net boiler output? Or gross input?

-Don
I didn't once consider this specifically for boilers, but rather usable for any stoker (or even for hand fired stoves for that matter). I believe it would represent net output. The efficiency used is 70%. The input assumption is for anthracite (as delivered) at 12,250 BTU's per pound.

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davidmcbeth3
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Coal Size/Type: nut/pea/anthra
Stove/Furnace Make: Hitzer
Stove/Furnace Model: 503

Post Sun. Mar. 20, 2016 12:20 am

The #s don't jive with the site's calculator values..

https://coalpail.com/fuel-comparison-calculator-home-heating

Any reason?

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sun. Mar. 20, 2016 4:24 am

davidmcbeth3 wrote:The #s don't jive with the site's calculator values..

https://coalpail.com/fuel-comparison-calculator-home-heating

Any reason?
How do you set up this websites "Fuel Comparison Calculator" to show BTUH output vs. lbs. burned per hour? It does not seem (to me at least) to be capable of doing this. Therefore it seems to not be possible to use it for any attempt to recreate the data which I have provided here. I need an education here, lest I relegate your reply to mere obfuscation. I stand behind my data as presented.

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StokerDon
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Stoker Coal Boiler: BairMatic BMC-500 with Van Wert VA400 Stoker, Gentleman Janitor GJ-671/EFM S-15 stoker, Van Wert VA-600
Hand Fed Coal Furnace: Harman SF3500
Coal Size/Type: Rice and Chestnut
Other Heating: Noth'in but COAL! Well, Maybe a little tiny bit of wood
Location: PA, Southern York County!

Post Sun. Mar. 20, 2016 8:40 am

Larry,

Your numbers come out very close to what I used to figure out the net output of the BairMatic/Van Wert.

VA400; 12.5 pounds per hour, x 12,250BTU = 153,125BTU / hour x 0.90 = 137,813 BTU x 80% = 110,250 BTU/hr actual.

The 0.90 is assuming 10% unburnt coal in the ash and the 80% is guesstimated boiler efficiency...

Using your numbers 12.5 pounds per hour comes out to 107,187.5BTU. I guess you used slightly higher unburnt content?

-Don

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sun. Mar. 20, 2016 9:10 am

Don, when the numbers get that close there is no need to quibble over any small difference. Your numbers and mine are the same for all practical purposes.

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StokerDon
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Joined: Mon. Nov. 11, 2013 11:17 am
Stoker Coal Boiler: BairMatic BMC-500 with Van Wert VA400 Stoker, Gentleman Janitor GJ-671/EFM S-15 stoker, Van Wert VA-600
Hand Fed Coal Furnace: Harman SF3500
Coal Size/Type: Rice and Chestnut
Other Heating: Noth'in but COAL! Well, Maybe a little tiny bit of wood
Location: PA, Southern York County!

Post Sun. Mar. 20, 2016 10:39 am

I agree. There are at least 2 factors that we are assuming, so for our purposes, we are "close enough".

-Don


Pacowy
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Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite
Location: Dalton, MA

Post Sun. Mar. 20, 2016 11:49 am

I think Don's way of accounting for unburned coal and boiler efficiency makes the computation a little more transparent. I believe the quantity both of you have computed would normally be referred to as "gross boiler output". AFAIK "net" boiler output refers to the amount of heat that is available at the installed radiation, net of distribution system losses (i.e., "pickup").

Mike

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sun. Mar. 20, 2016 12:37 pm

But (as stated previously) my calculations are generic, and not specific to boilers.

The important lessons to ponder are:

1) Whatever heat energy you manage to extract from your appliance, it was assuredly all in the coal to begin with. There is no such thing as energy from nothing. If you are not burning 12 lbs. per hour (as Don is doing) you are not delivering 100+K BTUH into your home.

2) Assuming that the end user is satisfied with their appliances heat output, many to most homes (Don excluded) apparently require much less heat than their owners initially (wildly) imagine. And the amazing reports of low lbs. per day burned (as seen on this forum) are a direct testimony to this. The furnaces of days past were obviously well oversized for the most part, and it is not necessary to repeat (or copy, as the case usually is) this mistake when considering a coal stove (with perhaps the exception of a boiler, where DHW and the "pick up factor" add extra demands not normally considered up front).

The unfortunate downside of this is that coal stoves are often ridiculously over-rated for BTUH. This stems from #2 above, combined with a total lack of understanding with regard to #1 above. If the misinformed consumer demands 100,000 BTUH output, then presto, the market provides solutions that accommodate (even if their stoves/furnaces, etc... are really more likely to deliver only say more on the order of 40,000 BTUH when pressed to the absolute limit).

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Rob R.
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Location: Chazy, NY

Post Sun. Mar. 20, 2016 1:29 pm

Most people don't know what they need, and the way many appliances are rated makes it tough to know what you are getting.

I think EFM and Van Wert are/were the most transparent about the amount of coal consumed and the heat output you could expect.

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davidmcbeth3
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Coal Size/Type: nut/pea/anthra
Stove/Furnace Make: Hitzer
Stove/Furnace Model: 503

Post Sun. Mar. 20, 2016 3:03 pm

lsayre wrote:
davidmcbeth3 wrote:The #s don't jive with the site's calculator values..

https://coalpail.com/fuel-comparison-calculator-home-heating

Any reason?
How do you set up this websites "Fuel Comparison Calculator" to show BTUH output vs. lbs. burned per hour? It does not seem (to me at least) to be capable of doing this. Therefore it seems to not be possible to use it for any attempt to recreate the data which I have provided here. I need an education here, lest I relegate your reply to mere obfuscation. I stand behind my data as presented.
Time is irrelevant .... X lbs coal yields Y BTU ..

does not matter if burned in an hour or 5 minutes

Time is not a factor in the BTU output of a given qty of coal .... so for the OP's first post, he can simply remove the "per hour" component and he would be "good enough - yielding to the prior posters' viewpoint". He could have said "in 5 minutes" and still be OK.

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sun. Mar. 20, 2016 3:08 pm

The "H" in BTUH proves that once again you do not have any form of a proper understanding here.

Pacowy
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Posts: 2867
Joined: Tue. Sep. 04, 2007 10:14 pm
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite
Location: Dalton, MA

Post Sun. Mar. 20, 2016 3:43 pm

Larry,

I don't think that it's reasonable to use exactly the same numbers for boilers vs. furnaces vs. other stoker appliances, which may differ substantially in their abilities to extract heat from combustion gases (e.g., due to heat exchange surface areas, use of water vs. air, etc.). Don's approach can tailor the numbers to fit the equipment in any given situation.

I also disagree with your reasoning and conclusions regarding the supposed oversizing of some/many older systems. In practice, a big boiler provides some bad and some good - somewhat higher standby losses vs. greater heat exchange surface and reserve capacity. If you try to translate lb/day directly to lb/hr through simple division, you overlook the fact that heating and DHW loads are not uniform over a 24 hour period. People who do that tend to be the ones wondering why they are taking a cold shower in a cold house at 6:30 am after a rough night in January. It is of little consolation that the system might catch up by mid-afternoon (e.g., when the heating load may be reduced via warmer daytime temps and solar gain). I think the Dead Men had a pretty good idea of what they were doing.

Mike

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lsayre
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Posts: 12781
Joined: Wed. Nov. 23, 2005 9:17 pm
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Location: N/E Ohio, between Medina and Wadsworth

Post Sun. Mar. 20, 2016 3:55 pm

Pacowy, I stated above that boilers provide an exception. I respect that you can't agree with my trying to simplify things so those with any coal burning appliance can find benefit from my numbers. If this was a discussion on boilers it would have been handled differently. But it is not a discussion on boilers.


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