6 meters is a good length chimney, mine is only a bit under 4 meters from the bottom of the stove to the top of the cowl.
Thanks - is your chimney lined or unlined?
On top of the stove is 1 meter of 150mm single skin stainless and on top of that is a 2m length of 150mm double skin insulated stainless, so I only have 2m of insulated same as you.
Trev, I'd like to understand the gas flow through the mass for the most recent iteration of your stove - can you point me to where in this thread I might see that? Thanks
Ignore the right side of that last picture it's from the previous secondary burn setup. It shows the gas flow through the mass on the left. Please note though that this only works for me because I have only 1 ton of mass in just about half a cubic meter. I was trying to maximize the heat extraction in a tiny space. If you try and do this with more mass on a larger scale it probably wont work well, a bell would be better for you then.
So as the colder weather approaches I have covered up my little hot plate for the winter as it is basically outside and a bit exposed, I suspect the damp will have more effect on the vermiculite than the heat!
Anyway I checked it over looking for cracks or deterioration but, the board is still sound with no further cracks.
So overall it has been a huge success, very easy and quick to build the basic core, although the steelwork did add up the cost, it was not really very expensive to build.
I would estimate that I lit around 80-90 fires, so not as much use as an indoor heater might have, I dont know how the vermiculite will stand after another 100 fires? Of course I am itching to build another one or at least do a few mods for next season……
The vermiculite board in my afterburner is now on it's 3rd year of use and still perfect, even the pieces with secondary air holes through them, heat wise it seems to be a very robust material. The two pieces I lined the sides of the firebox with last season got vertical cracks down the middle of them quite quickly after being installed, but other than that they are not showing much sign of degrading.
The Vortex core behaves quite differently without contraflow or mass, I haven't done a lot of experimentation with it under those conditions, so I'm interested in seeing what you discover. The afterburner window is a great tool for judging the quality of the burn, I can tell to within a few hundred ppm what the CO. reading will be just by watching it. At no point should the glass be sooting up, if it is something's wrong. Provided you're doing a well stacked top lit fire then blackening of the glass shows there's not enough back pressure in the system or it's not getting enough primary air.
I don't plan on doing much experimenting with my stove this season. The only improvement I can see now would be to reduce the system size so I don't have to live with the door open half the time so I may do that at some point. I will be making the proper door for the afterburner soon, will be nice to finally have that finished.
I have two hollow brick bells right alongside the stove so I could easily divert the flow into one just as an experiment but I dont have any use for stored heat it that situation.
I am more interested to see how high I can go with the top box as the space would make a good oven.
I have a crazy idea to raise up the stove so the vortex is more visible and comfortable to view but I would loose the hotplate function if I go to high, so…. I cant stop thinking about a grill under the stove. I wonder if I can use the heat from the firebox floor and also divert the flow to an area below the stove to make an ‘oven grill’ underneath the unit?
I have measured the heat on the outside of the doubled up vermiculite and it is around 125c so I would make the bottom of the firebox from refractory cement to get the underside much hotter, one benefit would be the ashes would keep the potential oven warm for a long time after the fire has died. I thought about using ceramic glass but I think it would crack under the ashes.
A 10mm piece of steel plate for the floor would maybe work better, would give you the radiant heat needed for the oven grill without the danger of cracking.
I have two hollow brick bells right alongside the stove so I could easily divert the flow into one just as an experiment but I dont have any use for stored heat it that situation.
I am more interested to see how high I can go with the top box as the space would make a good oven.
I have a crazy idea to raise up the stove so the vortex is more visible and comfortable to view but I would loose the hotplate function if I go to high, so…. I cant stop thinking about a grill under the stove. I wonder if I can use the heat from the firebox floor and also divert the flow to an area below the stove to make an ‘oven grill’ underneath the unit?
The Vermont Bun Baker is essentially that design. I'm sure you could do it, but you'll probably need a taller chimney stack to draw those gasses down to the oven and then back up to vent the exhaust.
The accuracy of info we share here is more important than my ego, your ego, or Peter's ego. None of us has exclusive ownership over the truth.
There no sound on the videos because the microphone on my camera stopped working years ago. The stove is not noisy, makes about the same as a typical woodstove.
Your modification is good it seems for the cooking directly on top of the port. Was this test done with secondary air or you ran with just the primary air? I suppose with secondary air it would be more efficient. martyn used this design (youtube link to his stove video www.youtube.com/watch?v=UH-0D9Tb6dQ) and his works quite well it seems with secondary air.
I will be building a similar with your design. Will try to post pictures/video once its finished.
This year I decided to try adapting the design to make a dedicated 4" cookstove. We often get people coming to the forum asking for small cooking stove designs for the 3rd world, and I've been wondering how well this would work.
To adapt it to a dedicated cookstove I wanted the hotplate above the port, as the main difficulty I see with getting heat into hotplates is the problem of laminar flow, where a layer of air separates the flame from the metal plate.
I removed the top chamber and cut some small pieces of vermiculite board to make the side and back walls of the afterburner. The top is now the hotplate and the exit of the afterburner is to the right and left sides (65mm wide x 75mm high). The chimney was the same as previous.
The increased resistance of the double exit channels seemed to have the same effect I observed on my 6" stove when I increased the surface area to volume ratio for the top chamber (Page 56).
The little cookstove ran excellent, the vortex stayed doggedly in the afterburner the whole burn. The fire ran for over an hour on the kindling I'd usually use to light the 6 incher. I boiled several large kettles of water on the cooktop while it was running.
The secondary air on my 4” stove does work in that is raises the temperature on the hot plate but I dont know if it effects how clean the fire burns? My stove also works very well without the secondary air supply, so without testing equipment, I cant really say if it is an improvement or not!
BenAlexanderT: Happy new year everybody. I wish you the best
Dec 31, 2020 15:06:14 GMT -8
Solomon: Anybody in Southern Oregon, in Jackson or Josephine counties?
Jan 16, 2021 21:54:43 GMT -8
gnomedome: i realsie this is from 2009
Apr 14, 2021 8:30:44 GMT -8
gnomedome: i realize this is from 2009 id love to see the photos from this ..as im looking to build a sauna soon similar to this .... if anyody sees this post obomartin@gmail.com..... the photos in this post did not show up
Apr 14, 2021 8:32:00 GMT -8
dcoyte: I am planning to use a cast iron heat exchanger out of a hydronic boiler set on top of my rocket stove, flue out the top. There will be a pump moving the water through the heat exchanger into an unpressurized 2000 gal tank. Any thoughts?
Dec 31, 2021 6:45:55 GMT -8
syekoms: Yes just found this forum am in Josephine county.
Jun 17, 2022 12:53:32 GMT -8
ecoenergyman: Hi new to forum I was wondering where to buy a masonry stove kit I could install myself ? Fran in ireland
Aug 1, 2022 17:39:58 GMT -8
natureman: I have been following this site for years
Aug 28, 2022 10:58:59 GMT -8
nendo: Can anyone on this forum point me in the direction of detailed plans for a rocket water heater please?
Oct 22, 2022 15:15:43 GMT -8
fierolepou: Hi everybody! Starting a project from scratch, this is a goldmine!
Dec 10, 2022 5:20:09 GMT -8
Solomon: Best way to not die in a house fire is to build a stove where the really hot stuff isn't near the flammable stuff.
Jan 10, 2023 11:34:39 GMT -8
beppe: Hi to everybpdy. I'm new about the rocket stoves and this forum
Aug 30, 2023 22:17:32 GMT -8
beppe: I have a living room+ kitchen of 75 square meters that was heated by an ordinary pellet stove with a power of 8KW.
Aug 30, 2023 22:19:29 GMT -8
beppe: I want to switch to a DIY pellet rocket stove but I haven't found yet a project that is really suitable for my situation. Is there anybody able to indicate to me a good detailed project?
Sept 4, 2023 9:05:15 GMT -8
sksshel: Yes, very happy with my DSR2. I had not heard about the DSR3. I probably won't be using it but I will look into it.
Oct 16, 2023 9:15:37 GMT -8
rockinon: I have some questions about a Rocket Mass Heater, as I am in progress of getting a place built in Arkansas in the mountains of NW Arkansas and it will be very helpful. How can I add pictures to illustrate what I am requesting
Jan 23, 2024 11:01:07 GMT -8
dd24: Bonjour, Quelqu'un expérimente t-il sur les poêles "bubafonya" ou "stopuva"? merci pour votre réponse!
Mar 2, 2024 10:32:32 GMT -8
marcios: Hi Trev, What dimensions did you keep for the top chamber?
May 9, 2024 13:41:47 GMT -8
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