Are BTU Figures Mainly a Bunch of Lies?

 
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mdrelyea
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Post by mdrelyea » Mon. Nov. 19, 2012 8:21 pm

franco b wrote:You also need commensurate heat exchange surface which these stoves don't have
You know, that's been on my mind lately. What about fins to increase the surface area? Are there stoves out there that have fins? For example, on my Alaska, the top of the firebox is right at the bottom of the plenum. It's just flat metal. What if it were covered in some sort of fins like an air cooled engine or a heatsink on a computer's processor? That would greatly increase the heat exchange surface area. While we're covering the outside, let's not forget about inside the firebox too.

Am I all wet? Has this idea been thought of before?

Mike

 
franco b
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Post by franco b » Mon. Nov. 19, 2012 8:35 pm

Anything to increase the surface area is effective. When finned copper was used in tankless coils it was 3 times as effective over smooth.

Most modern boilers have narrow flue passages with either fins or studs cast in. Rough cast iron has greater surface area than smooth and is a more effective heat exchanger.

There was a post where aluminum fins were used on the sides of a stove with good results.

 
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gizmo
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Post by gizmo » Mon. Nov. 19, 2012 8:38 pm

The one thing I learned about btu,s is,If you don't have enough,you
will be cold.


 
franco b
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Post by franco b » Mon. Nov. 19, 2012 8:52 pm

Flyer5 wrote:
franco b wrote:
As for boilers, if it does not have an IBR rating I would not trust it.
Why?
Years ago the problem was recognized that it was impossible to design a heating system unless boiler output figures could be relied on. The trade set up the Institute of Boiler and Radiator Manufacturers (IBR) to make standards for ratings. Now everybody could work to the same standard.

If there were standards for coal stoves you would not have such absurdities as a Vogelsang pot belly rated at 200,000 BtU.

 
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steamup
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Post by steamup » Tue. Nov. 20, 2012 10:38 am

Understand hand fired equipment is usually rated at peak fire. You cannot maintain peak fire in a hand fired piece of equipment without babysitting it. When you load it, the output is dimished until the fuel catches fire and then as the pile burns down, the output goes down.

Generally you have to oversize the hand fired equipment to compensate for the output curve. 15 to 20 percent minimum up to 35% oversizing is not uncommon.

Stoker equipment can maintain a more constant fire on demand.

The IBR system rates only liquid and gaseus fuel boilers.

 
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Flyer5
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Post by Flyer5 » Tue. Nov. 20, 2012 10:42 am

gizmo wrote:The one thing I learned about btu,s is,If you don't have enough,you
will be cold.
ROFLMAO. Thanks :D

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