Trev Ortex

I'm sooo jealous :/ Lucky if I get more than one fig a year from my trees. Just ate this years solitary offering, could easily have eaten a whole gallon of them

Have you tried it without the chimney cap? The chimney cap exit should be at least 1.5 times the cross sectional area of the chimney pipe or it will restrict flow - most aren't big enough. Also a spark screen alone can restrict the gas flow 50% easy. I'd put money on the cap being the main problem. One other situation I have seen like that where no one else could figure it out was the insulation inside the twin wall stove pipe was soaking wet, it happened because the pipe had been installed upside down.
Hope that's some help.

These threads may be of interest:

http://donkey32.proboards.com/thread/3489/3-ts-combustion?page=1&scrollTo=31964

http://donkey32.proboards.com/thread/3552/el-tornado-experimental-build-thread

paul wheaton wrote:I think we turned all the rss stuff off a couple of years ago.

Any chance you could turn it back on? PLEASE :)

This thread describes a J type rocket where the flu goes down from a 8" to 5" before it exits the house:
http://donkey32.proboards.com/thread/2439/tell-burning-clean

Nice oven, Ernie. Isn't it the same as a Russian Stove but in miniature?

James Fleming wrote:I am curious as to why the barrel is not wrapped in thermal mass (i.e. 3-6" of cob) although that would slow the initial radient heating of the room, wouldn't that provide a longer, more even heating of the room?

Yes but what about instant heat when you're room is cold. In a traditional masonry stove it takes about an hour before the heat makes it through the mass and starts heating the room, the drum gives it straight away and the mass stores it for the long run, so you have the best of both.

I'm guessing this is the result of the volume of the pipe verses the internal surface area? I know from Hydro-Electrics that below a certain size pipe the frictional losses quickly add up to 100% and nothing can be gained.

I've been wondering the same thing. I remember reading somewhere (on the Donkey32 Proboards Rocket Stove forum) that they only really work down to 3 inch, but I cant find where I read it now and there doesn't seem to be any other mention of it. I was thinking of building a scale model 2 inch batchbox rocket out of clay to see how it behaved. Sure would make experimenting a lot easier.