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Wood/coke burning stove chimney question
Irony - 23/8/11 at 09:34 AM

Is there any reason I cannot use this as my chimney flue in my workshop. Its zinc coated mild steel. The pot bellied stove wood be in the workshop and the chimney would go up about 1200mm from the stove and the make a 90 degree turn and go through the big wall. Another 90 degree turn to turn upwards and then a short straight to the outside world.

Flue Linky

My stove current vents immediately through the wall to the outside. I am pretty sure I lose nearly all the generated heat through the very short chimney. If I could have a longer chimney inside the workshop I think it might help heat the workshop up more effiecently

coozer - 23/8/11 at 09:43 AM

No problem as long as there's no combustible material anywhere near it.

Irony - 23/8/11 at 10:12 AM

quote:
Originally posted by coozer
No problem as long as there's no combustible material anywhere near it.


Can you define 'anywhere'. My workshop has wooden beams (A frames) that support the roof. How close would be exceptable in peoples opinions. I could easily fabricate some heat shields though if needed.

cliftyhanger - 23/8/11 at 10:20 AM

About a foot??
Make sure the chimney is painted black, it will radiate a lot more heat. Longer the chimney the better. I have wonderered if running one horizontally for the length of the garage would work before going up. Sounds wrong though.

Irony - 23/8/11 at 10:34 AM

quote:
Originally posted by cliftyhanger
About a foot??
Make sure the chimney is painted black, it will radiate a lot more heat. Longer the chimney the better. I have wonderered if running one horizontally for the length of the garage would work before going up. Sounds wrong though.


The black paint is a good idea. I have also wondered about running a pipe horizontally or even back and forth with lots of 90 degree bends. The bigger the surface area the better so maybe welding or riveting lots of old Computer heatsinks might work

MkIndy7 - 23/8/11 at 11:05 AM

Horizontal runs and 90deg bends are usually pretty big no no's where natural draught flues are concerned.. They add resistance to the flue so it has less pull to remove the products of combustion.

T66 - 23/8/11 at 11:22 AM

Ive had wood burners in the house, and also have a gas bottle patio heater with a 2' chimney.

When its stoked up you cannot sit within 2 ft of it. So dont worry about heat being lost. More about nothing getting singed.

MikeRJ - 23/8/11 at 12:30 PM

quote:
Originally posted by cliftyhanger
About a foot??
Make sure the chimney is painted black, it will radiate a lot more heat.


The visible colour makes hardly any difference to the emissivity at the far infra-red wavelengths involved. As long as the pipe doesn't have a polished metal finish then a coat of paint isn't likely to improve things much.

cliftyhanger - 23/8/11 at 12:56 PM

I will bow to what I suspect is greater knowledge. My advice was based on a simple experiment done with a leslie cube at skool. There is a higher measurable temp at 20mm distance on a matt black side over the silver polished side.