clean, sustainable wood burning

paul wheaton

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The purpose of this video is to give folks an idea of how clean the exhaust is while running a rocket mass heater in Missoula, Montana.

When we first start it, there will be smoke. And there was smoke in the middle of the burn sometimes, but I think that most of that has to do with things that need more design improvements. For most of the
time, the exhaust was a lot like what is shown in the video - there is fire, but no smoke. Marci Anderson gets her nose right in there.

Another important thing to note is that the temperature of the exhaust: see how we have a hot, clean fire burning and guido does not burn his hand when he puts it in the exhaust. It feels warm, but not hot. We measured it at about 90 degrees when the barrel was at about 850 degrees.

I show the materials being moved by the freecycles folks from the freecycles HQ in Missoula to Caras Park (downtown Missoula). Then a bit of building it.

This rocket mass heater is a prototype for some variations. A wood box shows a different aesthetic, a much taller heat riser design, using dry, loose fill (rocks and sand). This should be a lighter design than other rocket mass heaters - so it might be good for places that have a wood floor.

This might also be the fastest time a rocket mass heater was ever built: an hour and fifteen minutes.

http://www.youtube.com/watch?v=kGaGtO8MkQk

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Icu4dzs

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I've been looking at YouTubes(exclusively instead of TV) about rocket mass heaters and they fascinate me. I am still a bit confused about how to get the perlite to stay inside the outer drum. Perhaps I am doing something wrong.

I will watch the video and try again. What I want to know is: "Even though there is very little exhaust, do you still have to vent it outside in order to avoid Carbon Monoxide? I have a large shop and can't work in the -30 F temperatures because it is so hard to heat that big space. Obviously with a steel cylinder of a building you would imagine that with no insulation this might be kind of tough.

Can you suggest an exhaust system to allow the POC to escape and not let the -30 F back in the building?

The other question I have is what size rocket mass heater matches what size space? I have a 30 x 30 shop space (go ahead and drool, it is only ONE of my wonderful farm shop spaces...he said snidely (LOL)
thanks
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k15n1

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You should measure the temp of the exhaust gasses in the center of the flue, perhaps at several points along it's length. It will give you qualitative information about how well you're making use of the heat generated in that nice hot fire.

BTW, engineers use input and output temperatures to measure efficiency. You may not be terribly interested in doing that yourself, but the measurements are useful, regardless of the use.
 
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