Round Flue Vs . Square Flue

Round flue vs . square flue

PostBy: Den034071 On: Sat Apr 22, 2017 10:43 am

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Re: Round flue vs . square flue

PostBy: Hambden Bob On: Sat Apr 22, 2017 11:01 am

Seems that's always been a Deep Discussion here,and rightfully so...

The Round vs Square/Rectangular Theories have been a part of Stove Design Discussion for better Combustion Characteristics and Thermodynamics.....

I'm towards the Round Crowd myself. The Cylindrical Swirl seems to make it go well,in less than Laymans' Terms !
Hambden Bob
 
Hot Air Coal Stoker Stove: Harman 1998 Magnum Stoker
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Re: Round flue vs . square flue

PostBy: coaledsweat On: Sat Apr 22, 2017 11:31 am

Not sure if I'm correct here but I'll give it a shot. The area to surface ratio is better on a round flue. Along the surface of the flue, the movement of gasses is stalled and turbulant, at center, the flow is laminar. The less surface area, the lower the amount of velocity upset per square inch of cross section. Make sense?
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Stoker Coal Boiler: Axeman Anderson 260M
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Re: Round flue vs . square flue

PostBy: Rob R. On: Sat Apr 22, 2017 12:24 pm

I think insulation and height makes more difference than square or round, assuming the flue is properly sized.

Insulated round flue would be my top choice.
Rob R.
 
Stoker Coal Boiler: EFM DF520
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Re: Round flue vs . square flue

PostBy: Sunny Boy On: Sun Apr 23, 2017 6:54 am

Rob R. wrote:I think insulation and height makes more difference than square or round, assuming the flue is properly sized.

Insulated round flue would be my top choice.


That would be my assumption too.

It's heat differential and retention of that heat, plus height, that is the driving force to make draft.

I had a 3 story high, 6 inch round single-wall pipe chimney for my potbelly stove. Very difficult to not have back drafts when starting a cold stove. And once the stove was running, the draft was too poor to idle the stove down because of the heat loss in the chimney.

I have a tall brick chimney now, no liner with rounded corners. My range has about the same coal capacity as my small potbelly stove was. With this brick chimney - built back in the days at the height of coal use - it is easy to start a fire, and the range will idle for hours at a steady burn as low as .005 mano reading.

Paul
Sunny Boy
 
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Re: Round flue vs . square flue

PostBy: oliver power On: Sun Apr 23, 2017 7:40 am

I agree with others. Really doesn't make a difference. I do like the round flue better. Don't really know why. MAYBE a little stronger than the square flue. One thing for sure, the round would give more room for insulation. I put round in my masonry chimney.
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Re: Round flue vs . square flue

PostBy: waldo lemieux On: Sun Apr 23, 2017 7:52 am

I had a round flue before I switched to coal. It was always easier to clean a round flue with creosote buildup, no corners...
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Stove/Furnace Make: efm
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Re: Round flue vs . square flue

PostBy: freetown fred On: Sun Apr 23, 2017 7:55 am

That's why they make square brushes WL. LOL
freetown fred
 
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Re: Round flue vs . square flue

PostBy: waldo lemieux On: Sun Apr 23, 2017 8:05 am

They make brushes that are square???? :oops: I always bought a oversize round brush and took it down to my barber to make it square, used to charge me extra to get his scissors sharpened after....
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Stove/Furnace Make: efm
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Re: Round flue vs . square flue

PostBy: freetown fred On: Sun Apr 23, 2017 8:14 am

That's a good barber my young friend :)
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
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