Rocket stove setups without a vertical stack?

[ziggy]

Hi all. I was curious to hear from anyone who has built (or seen) a rocket stove setup without a vertical stack - wherein the flue pipe simply exits the building horizontally. I have heard from Ianto that it is possible, and it's what I am hoping to do with my stove setup, but I have concerns that it may not actually work.

I will be using a 55 gallon drum as part of my heat riser, and a 6" flue pipe. The flue pipe will snake through a cob bed (making two 180 degree turns) before running straight through a bench, and out the south wall of my home. I'm hoping that I do not have to resort to adding a vertical stack outside of the house.

Any thoughts?

Thanks!

[Donkey]

I've run stoves without the stack. I've seen ones that ran sluggishly with the stack on and improved with the stack pulled off..
As a general rule though, your probably better off WITH the stack on. As long as there is enough heat left over to drive it, it should (almost always) improve performance. Also, there are times when smoke will spill out of your stove. Wood smoke has toxins in it, better to release it overhead, out of breathing range.

From your other post, I'm assuming that your in-bench pipe will have a fairly long run.
A tallish heat riser will help. Also, since you plan to double back to the beginning again, you could lay the last bit of pipe up close enough to the business end to steal a little heat and boost it up the chimney.

I'd say if you REALLY don't want the chimney, you could probably get away with it.. First you'll want an exceptionally well insulated firebox and heat riser to burn ALL of the fuel and minimize toxic exhaust. You will need to pay close attention to volume changes within your stove. A wide spot in the wrong place can foil the "pressure pump" action that you will need to make up for the loss of the chimney, and a too narrow spot can choke the works. It may be helpful to step down in pipe size just a bit towards the final leg in the bench too.

I would also say that if your home is in a bowl, it's possible that flue gasses could pool and create a dangerous condition. It would be best if your exhaust pops out on a side of the building where there is a downhill slope.. Just in case..

[ziggy]

Thanks for the reply...

I just hooked up 25 feet of flue pipe to my stove, lit a test fire, and was happy to see that the stove is drawing without a vertical stack. The flue pipe exits the south face of the house. I am hopeful.