I initially posted this simplistic maximum BTU's calculating formula within another thread, but in order to attempt a wild stab at unifying the BTU output ratings of the various hand fired stoves across the many brands as well as the many decades, please give a go at calculating your stoves maximum rated BTU's based upon this very simple formula, and report your results. Measurements should be taken from Inside of firebrick to inside of firebrick. Only concerned with length and width (or diameter if round). No concern for firebox depth. I don't want to complicate things much. When you report your calculated BTU's as derived from this formula, also give us the manufacturers listed BTU's for comparison if available.

If the firebox is square or rectangular: L x W x 375 = Maximum BTU's

If the firebox is round: Radius Squared x 3.1416 x 375 = Maximum BTU's

Disclaimer: Please do not attempt taking measurements while stove is hot!

If the firebox is square or rectangular: L x W x 375 = Maximum BTU's

If the firebox is round: Radius Squared x 3.1416 x 375 = Maximum BTU's

Disclaimer: Please do not attempt taking measurements while stove is hot!

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

So CRAP Larry, this is dead till spring?????????????? -----------------

- freetown fred
**Hand Fed Coal Stove:**HITZER 50-93**Coal Size/Type:**BLASCHAK Nut/Stove mix

freetown fred wrote:So CRAP Larry, this is dead till spring?????????????? -----------------

No guesses allowed, so it very well could be!

Last edited by lsayre on Fri Jan 03, 2014 8:32 pm, edited 1 time in total.

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

Damn! I wish I'd read your disclaimer Larry. I got blisters on my fingers!!

- coalkirk
**Stoker Coal Boiler:**Harman VF3000**Coal Size/Type:**antrhcite/rice coal

coalkirk wrote:Damn! I wish I'd read your disclaimer Larry. I got blisters on my fingers!!

Ouch!

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

Larry,I have 20"w x 21.50"d and using your formula I came up with 161,250 and the manufacture says its 100,000 so I have to ask why do you need to know?

Keepaeyeonit.

PS. you owe me a new tape(12' Stanley)

Keepaeyeonit.

PS. you owe me a new tape(12' Stanley)

- Keepaeyeonit
**Hand Fed Coal Stove:**Hitzer 983 insert**Coal Size/Type:**Mammoth nut**Other Heating:**oil furnace,and a crappy heat pump

Keepaeyeonit wrote:Larry,I have 20"w x 21.50"d and using your formula I came up with 161,250 and the manufacture says its 100,000 so I have to ask why do you need to know?

Keepaeyeonit.

PS. you owe me a new tape(12' Stanley)

Sorry about the tape! Did you read the disclaimer? Are those inside to inside of the firebrick measurements? The formula seems to work well for DS Machine stoves. Perhaps inserts work differently? You know me though. Always curious.

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

Larry knew someone would try to get a new tape out of him. That's what the disclaimer is for.......Keepaeyeonit wrote:Larry,I have 20"w x 21.50"d and using your formula I came up with 161,250 and the manufacture says its 100,000 so I have to ask why do you need to know?

Keepaeyeonit.

PS. you owe me a new tape(12' Stanley)

- oliver power
**Stoker Coal Boiler:**KEYSTOKER Kaa-2**Hand Fed Coal Stove:**Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)**Baseburners & Antiques:**MANY (Mostly when burning wood)**Stove/Furnace Make:**HITZER / KEYSTOKER**Stove/Furnace Model:**50-93 & 30-95 , Kaa-2

Uh, How would that work for a "V" shaped firebox??

- Lightning
**Hand Fed Coal Furnace:**Clayton 1537G**Coal Size/Type:**Nut/Stove Size Mix

Lightning wrote:Uh, How would that work for a "V" shaped firebox??

I just knew there would be kinks in this. Keeping it simple isn't going to be as simple as I thought! Already burnt fingers and a toasted tape measure, and now this!

Where does the majority of the coal burn at? How about 2" down from the top of the 'V' sloped firebricks?

Last edited by lsayre on Fri Jan 03, 2014 8:50 pm, edited 1 time in total.

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

Yes sir, Inside of the brick(Hitzers dimensions are 20.50W x 21.25D)and I even have brick along the front that I added and I didn't see your disclaimer you have to remember I'm a coal burning Neanderthal .Keepaeyeonit

- Keepaeyeonit
**Hand Fed Coal Stove:**Hitzer 983 insert**Coal Size/Type:**Mammoth nut**Other Heating:**oil furnace,and a crappy heat pump

Keepaeyeonit wrote:Yes sir, Inside of the brick(Hitzers dimensions are 20.50W x 21.25D)and I even have brick along the front that I added and I didn't see your disclaimer you have to remember I'm a coal burning Neanderthal .Keepaeyeonit

Perhaps you have a very conservatively rated heat monster there!

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

DS Machine model 1627

Advertised BTU= 170,000

Firebox dimensions is a huge 16"x 27", hence model 1627

I don't know about it's efficiency but it dam sure is cranking out some great heat in tonight's below zero weather we're having, I actually had the house too hot last night at 75*

Advertised BTU= 170,000

Firebox dimensions is a huge 16"x 27", hence model 1627

I don't know about it's efficiency but it dam sure is cranking out some great heat in tonight's below zero weather we're having, I actually had the house too hot last night at 75*

Last edited by Bruce M on Fri Jan 03, 2014 8:59 pm, edited 1 time in total.

- Bruce M
**Hand Fed Coal Stove:**DS Machine 1627 basement stove

The formula for a trapezoid (I'm assuming that's what a cross section of your fire box would be) is the average width multiplied by the height.

So if I understand your formula correctly it would be.

(Width of bricks at top + width of grate / 2), x length of firebox, x 375= maximum btu output

So if I understand your formula correctly it would be.

(Width of bricks at top + width of grate / 2), x length of firebox, x 375= maximum btu output

- carlherrnstein
**Hot Air Coal Stoker Stove:**combustioneer model 77B**Coal Size/Type:**pea stoker/Ohio bituminous

Bruce M wrote:DS Machine model 1627

Advertised BTU= 170,000

Firebox dimensions is a huge 16"x 27", hence model 1627

I don't know about it's efficiency but it dam sure is cranking out some great heat in tonight's below zero weather we're having, I actually had the house too hot last night at 75*

Thanks Bruce! 16" x 27" x 375 = 162,000 max BTU's

As I said, the DS Machine stoves seem to work fairly well with this formula.

- lsayre
**Stoker Coal Boiler:**AHS S130 Coal Gun**Coal Size/Type:**Stockton Anthracite Pea**Other Heating:**Resistance Boiler (13.5 KW)

- View Posts: Unanswered • Active

NEPA Crossroads is a creation of Nepadigital.Com ©2014 • Contact Admin | Terms of Use | Privacy Policy

Powered by phpBB © phpBB Group