Does a Fan Produce More Heat or Just Blow the Air around?

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: lsayre On: Thu Jan 16, 2014 8:27 am

Lightning wrote:Larry, pardon me for saying so but I think you being a bit stubborn at this point lol. I have to agree,, the fan doesn't produce any heat. Hell the stove doesn't produce any heat either. It's merely a heat transfer station. The only thing producing heat is the coal.

The elevated volume of air moving across the stove's surface is causing better heat transfer efficiency. I believe this was the original poster's intention.


Then the OP should have used words more appropriate to that end. See the capital P in Produce in the subject line. The word should have been "induce" (as in for example: induce the potential for more heat given that voltage must remain constant), not produce.

A new riddle. How many BTU's would a resistance heater produce if a fan was blowing across its resistance element to lower the resistance, but the power company did not assure constant voltage, but rather allowed the voltage to drop and instead guarranteed that you would always receive a constant current flow?

V- IR
I = V/R

If the current flow stays the same the BTU's stay the same. Energy (the number of flowing electrons) in = energy (BTU's) out
Last edited by lsayre on Thu Jan 16, 2014 8:28 am, edited 1 time in total.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (if I ever get it fixed)

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: freetown fred On: Thu Jan 16, 2014 8:28 am

Ya know, there's a real fine line between discussion & mental masturbation. Just an old farmers observations :)
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: waldo lemieux On: Thu Jan 16, 2014 8:54 am

^^^ :rofl:

Larry must be bored, it took 14 pages for him to point out that the op should have phrased the question a bit differently, though I think everyone (including Larry) knew what the real question was. Oh well , I was enjoying the mastrabation :woot:
waldo lemieux
 
Stove/Furnace Make: efm
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Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: Lightning On: Thu Jan 16, 2014 9:17 am

Is this a trick question?
Volts x amps equals watts
Watts define btu output.
If volts drop, more amperage would be needed to maintain heat output. Fan or no fan. :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: dcrane On: Thu Jan 16, 2014 10:09 am

Lightning wrote:Is this a trick question?
Volts x amps equals watts
Watts define btu output.
If volts drop, more amperage would be needed to maintain heat output. Fan or no fan. :D


IDK man... someone got larrys head going :cry:
We need some large Tubs of water fast! or RUN!
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dcrane
 
Hand Fed Coal Stove: Crane 404

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: kstills On: Thu Jan 16, 2014 12:07 pm

tony17112acst wrote:I'm the OP. *bows*

My assumption in my question is that the same amount of energy is used inside the stove with and without the fan.

Please consider the original question with say, an electric resistance coil heater set up inside of the stove. This heater can only put out a certain number of BTU's ...say 50,000 BTU's ...and no more!

So I ask you recent posters: Will more heat transfer to the room by pointing a fan on the stove that contains this 50,000 BTU electric heater? You cannot claim that more heat will come out of the electric heater inside the stove (because it's impossible). The clear answer is "yes." It is "yes" because a fan will cause a lower temp on the outside of the stove and more heat will transfer to the room and not out the pipe/chimney because of the principle that exists that heat transfers through a medium more quickly as the temperature difference is greater on either side of it.


EFFICIENCY IS A GOOD THING. BUT...
Solid fuel appliances only work because of the The Chimney Effect - by losing a certain amount of heat into the chimney, they make the gases there rise and so safely evacuate smoke and pull fresh air onto the fuel to make it burn. An appliance with a very high efficiency is losing less heat into the chimney and, unless its chimney is perfect, it may encounter problems in generating enough draught to make it burn effectively, or safely evacuate smoke, it may be problematic in lighting-up from cold and may not keep the waste gases hot enough to prevent tar from condensing inside the flue. This is why appliances with the very highest efficiencies, some above 90% (net), almost invariably require an electric chimney fan.


Apples-oranges....
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: kstills On: Thu Jan 16, 2014 12:11 pm

And this:

MEASURING EFFICIENCY and OUTPUT
It is not normally practical to directly measure the heat output of a solid fuel appliance, instead, samples of the waste flue gas are taken - usually using a flue gas analyser the chemical composition of the gas indicates how efficiently the fuel has been burned and its temperature indicates how much of the heat generated has been captured and how much is lost into the chimney.

Given the temperature of and percentage of carbon dioxide (CO2) in the exiting flue gas, the, moderately accurate, Siegert's formula gives the efficiency from:


100 - ( (MeanFlueTemp ºC - MeanRoomTemp ºC) x (A1 / CO2%) )

(Where A1 is: Anthracite=0.683, Coke=0.290, Bituminous Coal=0.672, Lignite=1, Peat=0.7, Dry Wood=0.650)

The heat output in kW is then calculated from:


(Efficiency x Potential heat in kW x Fuel burned in kg) / Burn time in hours

...using data on the Fuel Properties page


It takes a lot of page views to come up with relevant data...
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: freetown fred On: Thu Jan 16, 2014 4:17 pm

As in, one mans relevant is another mans regurgitate :clap: toothy
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: Sunny Boy On: Thu Jan 16, 2014 4:29 pm

freetown fred wrote:As in, one mans relevant is another mans regurgitate :clap: toothy



:D

Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: kstills On: Thu Jan 16, 2014 4:35 pm

freetown fred wrote:As in, one mans relevant is another mans regurgitate :clap: toothy


I suppose we all have different levels of interest on how things work.

Cheers.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: PJT On: Fri Jan 17, 2014 12:18 am

...is it over?...
PJT
 
Baseburners & Antiques: Magee Royal Oak; Glenwood Modern Oak 116
Other Heating: propane

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: oliver power On: Fri Jan 17, 2014 7:15 am

PJT wrote:...is it over?...
I sure hope so......
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)
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Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: freetown fred On: Fri Jan 17, 2014 7:47 am

WAIT----was that the fat lady I heard singing??? :clap: toothy
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Does a Fan Produce More Heat or Just Blow the Air around?

PostBy: Sunny Boy On: Fri Jan 17, 2014 8:02 am

freetown fred wrote:WAIT----was that the fat lady I heard singing??? :clap: toothy


Lets hope she doesn't have a fan club ? :D

Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

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