I found out very quickly that with a horizontal pipe extending from the rocket stove to the outside of the house, that even a slight gust of wind will blow even a little exhaust back into the fire and put it out immediately. This seems to be so because the exhaust gas once it leaves the heat riser is so depleted of oxygen because of such an efficient burn, that it simply will not sustain fire. This became very clear to me when I was trying to re-energize the draft a little bit by putting a propane torch slightly into the fire tunnel, and as soon as the slightest bit of gust hit the side of the house, the slight amount of exhaust blowback put the flame of the torch right out.
I got an 8" " whirly bird" vent from Lomanco, I put a tee in the 6" horizontal stove pie and adapted the 6" to 8" on the top of the tee and put the vent on top of that, (I used a tee, so that I could put a cap on the end to be able to open it as a clean out) and now it works perfectly, totally unaffected by whatever the wind does. (be sure to put some weep holes in the bottom of the horizontal 6" pipe to drain the condensation. The big test will be to see what happens to the condensate when it gets to 20 below. I may have to use expensive insulated pipe, or try wrapping it with fiber glass insulation and ten wrapping it some more with shrink wrap. Hopefully it will not come to that.
The 8" model from lomanco comes without the base, which you do not need. Becuase they make so few of them, you have to pay a lot more for the 8" vent than the 12" model, but I do not know if you can take the base off odf the 12 in model, and I think it might put up rtoo much wind resistance in a storm.
I had expected that the heat from the exhaust was going to make the vern turbine rotate in the absence of wind, as it would on a rook exhausting hot air in the attic. As it turns out, there is so little exhaust from the vent, that it will not make the turbine rotate when there is no wind, you just get water vapor consinging once it tits the cold air flowing thought the blades of the vent without turning it.
Don't listen to Steve. Just read this tiny ad:
Switching from electric heat to a rocket mass heater reduces your carbon footprint as much as parking 7 cars