Roo said:
Marty S said:
Guyz:
Lots of fodder to ruminate. I'll do so and be back.
Aye,
Marty
We'll be here ya ole'
goat.
Sorry, I took so long.
I've attempted to address your questions and to correct misconceptions in your previous posts in this thread. I have found material which supports my above posted statements and which I stand behind with the caveat that I do not have all the answers. Being challenged on concepts I have held as valid is a learning experience for me I welcome with an open mind.
So, here we go...
ABOUT “EFFICIENCY” (Attn: Precaud, Roo)
“Heating efficiency shows how rapidly the heat produced by the fire is transferred to the room. It does not, however, measure how comfortable the room will be, only how quickly the heat is delivered.
A combination of high combustion efficiency and moderate heat transfer efficiency is the ideal in any wood burner.
Metal stoves and wood furnaces typically have relatively lower combustion efficiencies and relatively higher heat transfer efficiencies ... Metal transmits heat very well, in fact within minutes of the fire being lit. Similarly, the wood furnace heats the air instantly and immediately distributes this hot air to the home. This makes for a very responsive heater, which is able to throw heat into a space very quickly. However, this fast response comes with two critical drawbacks.
Firstly, it becomes very difficult to regulate the heat output so that it is comfortable.
If the heat output (heat transfer) is controlled by restricting the air supply, combustion efficiency drops off drastically, causing a smoky fire, huge amounts of air pollution and probably creosote deposits.
If the air supply is not restricted, combustion efficiency improves but the room becomes too hot and dry, which also has an adverse effect on the health of the occupants. This clearly demonstrates that
high heat transfer efficiency is not a desirable quality in a wood heater.
Well said ( or quoted ) Thats is a great job of describing how a 55 GALLON BARREL STOVE works and with that i totally agree. Again with taking information and twisting it around and blowing out of scale. unfortunately a modern EPA wood stove that is worth a salt is NOT going to work like the old fashion barrel stove and characteristic as you describe.
Secondly, combustion efficiencies of metal stoves and furnaces are comparatively low, because the heat is given off too quickly and the temperature of the fire cannot build to the point where the gases are fully burned. Most metal stoves and furnaces cannot be burned safely over 900 degrees F. (482 deg. C) because the metal becomes too hot and the unit is severely "over-fired". They are usually not comfortable to be around when burned at over 400 degrees F. (204 deg. C), due to their high heat transfer efficiency.”
Again , Old data and information on an ole barrel style stove the modern EPA stoves run higher and hotter temps inside the fire box even as you had stated of 1100° - 1400° with secondary combustion , the placement of steel baffles , modern firebricks , heat blankets , boards and heat baffles keep the inside firebox and combustion chamber hot and takes the wood burning 50% efficiency up to 74% - 80% through secondary combustion.
Now Marty if "YOU" would just bring "YOURSELF" up to speed and information with modern EPA wood stoves and how they work you would have a better understanding of what everybody is talking about. You debating technology from 50 years ago of steel stoves on a forum of newer modern EPA stoves is kinda of pointless and misleading.
(broken link removed)
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ABOUT EFFICIENCY AND THERMAL MASS (Attn: Precaud, Stoveguy2, Roo)
“Heat transfer efficiency (thermal efficiency).
How much of the heat generated in the firebox escapes through the chimney into the atmosphere (stack loss) depends on the firing strategy and the thermal mass of the heater. Newer metal stoves and fireplace inserts with firebrick lining are designed to be clean burning but still have poor thermal efficiency because they lack a thermal mass that functions as a heat exchanger. “
(broken link removed to http://www.hotrockmasonry.com/PDFs/Planning_Guide.pdf)
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and
“Heating efficiency of any wood heater depends on 2 factors:
(1) Combustion Efficiency - how completely it burns the wood and
(2) Transfer Efficiency - how much of the fire’s heat gets into the room rather than going up the flue.
How efficient your wood heater operates depends on 2 more factors:
(1) Installation - location on outside v inside wall. Heater too big for house? Flue draw?
(2) Operation - Is wood green? Firebox load? Adequate air?
Your operating technique accounts for the largest variations in your woodstove’s heating efficiency.
[Unless you burn consistently above 1000* F] most of your [$$] investment in wood goes up in smoke.”
www.baaqmd.gov “Woodburning Handbook”
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ABOUT AIR RESTRICTION (Attn Roo)
“Wood needs 200% - 300% excess air [above required for chemical conversions], or complete combustion will be hard toachieve...”
All Fuels Expo, 1996, Burlington, VT
“Course in Heating Systems” by Norbert Senf
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Hope this helps.
Aye,
Marty