My 1st RMH build!

Thankyou Andor for the kudos. Hey Martin, ya I saw your video with the duct pipe changed & raised off the floor, good deal! I now would prefer a DOWN position at the outside ground exit of the pipe since you have changed/raised the duct pipe in the basement~~nearly unwavering flow to the grass should give decent results & naturally drain all the condensate~~but you gotta continue testing that last leg, for YOUR PERSONAL BEST RESULTS.


But the 'to the top' outside chimney idea, I favor even tho it costs ALOT MORE $$, & dangerous working off the ground, it is difficult for me to resist the natural draft of a conventional "3+ feet above the peak, chimney", but it helps for that type chimney to be run near the burn barrel, to gain some heat and escalate the exh. flow (hope that makes sense) not sure that a shiny new chrome pipe up the side will go undetected by the local 'chimney police', I would probably leave it at grass level for now, until you get some decent flow, and have decided on the best mass handling.

james beam

Here she is, surgery done, all mortared back together. See my vid of completed work and first burn:
http://youtu.be/25uLStzrxEs

You will see the "chip chunks" burning in the feed tube. These burned great and do so anytime I have them piled in there. Problem is that any other form of wood fuel I put in ends up smoking back and flaming back, even if the feed tube is choked back. I slowly burned the mass dry and continued to burn for over 48 hours, feeding the fire hourly around the clock. 30 deg outside, furnace turned off and she kept my 4000 sq' home at 65 deg! I have SO much belief in this system, just need to work a few more bugs out.

Next, I will be removing the outer brick and perlite from around the feed tube in hopes of keeping them from getting so hot as to allow early combustion of fuel as previously mentioned.

OK folks, we are still at it. Thank you all for such excellent advise! Please keep it coming.

So good to hear this is capable of heating a big house, sounds like it just needs to be made big enough like yours and fire it most of the day to get the benefit. Hope you get it up and running for good soon, keep us posted.

Hey Martin, so far... so great! I notice in your pix of 'fully open cavity', the burn pattern on the lid of the cavity shows a smoke/soot pattern that follows the joint in the foundation rocks (your pix shows the hoe handle very near this area)...anyway, verify your not leaking at that joint in the stones. In another pix, interesting smoke pattern was on your now removed 'mass wall slab', it shows the brownish smoke/soot patterns flowing toward each baffle chamber, until the baffles caused complete flow disruption. At approx. half way down the 'mass wall slab', the 4th or 5th baffle, then the brownish smoke/soot pattern changes drastically, demonstrating exactly where your exh. flow stopped within the original setup. The 'mass wall slab' even shows a 1" wide heat band that follows the baffled roof, all very interesting.

I'm glad your finding out the hard way about 'dry wood', so scrounge your wood now, for next year & lots of it. The thing is with 'the works' in the basement, I would recommend being overly cautious about stored wood down there, and ummmmmmm you need a real fire extinguisher or 2 in the working area, a bucket of water is good too have handy also, in case you feel like putting something in it quick! As I'm sure your well aware, your house is not use to the drying action of 100 degree temps IN the basement, so floor joists and decking is going to dry out, and become tender to even a wild spark. And you have already noted the flare up of the supply wood while in the feed tube. Just for fun imagine a bunch of assorted wood laying around, some newspaper, some sawdust, and somehow a stick of old 'devil's claw' got shoved in the stove, this stuff pops like popcorn and literally shoots sparks when well lit. Something like that WILL happen sooner or later, so be prepared about the least or an unseen spark or smolder.

All I can say is ~~~Merrrrrrrryyy Christmas~~~

james beam

Martin Seidel wrote:[color=blue]Question is, why do I still have smoke/flame back even after complete bypass of the baffles?

Martin,
Maybe, just maybe, you need to cool the feed. The theory is this: when the whole feed tube is insulated, it could be that the self-combustion temperature of the fuel is reached at some point in time. To tackle that problem, try to confine the insulation to the lower portion of the feed, the level of the burn tunnel. As another measure, place a piece of a smaller drum on top of the feed tube. This will dissipate heat into the room, keeping the content of the feed cooler. Also, by adding this the combustion air will come in from above almost exclusively. This will help as well to cool the feed more efficiently.

Hey martin, & peter berg, how about this example that kirk mobert has posted a PIX of in this thread, as a simple fixture of cooling the feed tube, is this even close to what your suggesting peter?

https://permies.com/t/12203/stoves/Rocket-Stove-rockety (look for post Saturday, February 18, 2012 9:27:11 PM from kirk mobert)

It comes to mind martin, that because your kina conditioned to 'blower enhanced fire',( LOL which is very addictive! )~~ you might read also few thoughts in that thread about 'time & efficient combustion'.

I think you might provide a condensation weep hole in the lowest point of your your duct pipe, maybe a collector tray like used with an icebox.

Will you be fastening the duct connections with screws or rivets for structural integrity?

Regular duct tape is really stinkycaustic smelling stuff when it is used in RMH exh. duct work, I think I read somewhere that others are sealing joints by using heavy guage aluminum foil tape, AKA: 200 mph tape.~~just a suggestion.

Can you backfill around the duct pipe as it goes thru the baffled area, as well as the duct pipe on the floor? Remember the idea is to get as much heat into the mass, and whatever is left over goes outside.

You might configure something to protect the duct pipe from getting crushed when stepped on, dirt & rubble backfill will NOT prevent the duct pipe from being crushed.

james beam

WOO HOO! Awesome, Martin-- I think you are on your way to a finished system, with just a few tune-ups:

1) As JB said, backfill? I assume you plan on doing this around all areas of your new ducting. The air gap between the pipe and your mass is now acting as an insulator-- slowing the transfer of heat from the pipe to the mass. Conduction works much better here, so fill 'er up!

2) I think that you've got to go back to bringing the exhaust up off the floor. Have you been able to measure your final temps at the end of your system with these new improvements? There might be too much heat loss with the full run along the dirt floor. You could compromise and only cob in a short run, like 6 or 8 feet, and then go vertical to the level of your exit at the exterior wall; giving you a big thermal battery, but still enough heat to get all of the gases out.

Keep on posting pics...looking good:)

Chris

PS-- I've got a radical little design I'm trying to get put in before the new year.. will be posting a thread with plans and details soon. keep a look out

james beam wrote:Hey martin, & peter berg, how about this example that kirk mobert has posted a PIX of in this thread, as a simple fixture of cooling the feed tube, is this even close to what your suggesting peter?

This will help as well to some extent, I'm very sure about that. However, it's not a medicine for all diseases.
By the way, the p-channel or Peter Channel is of my own design.

Peter Berg wrote:

Martin Seidel wrote:Question is, why do I still have smoke/flame back even after complete bypass of the baffles?

Martin,
Maybe, just maybe, you need to cool the feed. The theory is this: when the whole feed tube is insulated, it could be that the self-combustion temperature of the fuel is reached at some point in time. To tackle that problem, try to confine the insulation to the lower portion of the feed, the level of the burn tunnel. As another measure, place a piece of a smaller drum on top of the feed tube. This will dissipate heat into the room, keeping the content of the feed cooler. Also, by adding this the combustion air will come in from above almost exclusively. This will help as well to cool the feed more efficiently.

Thank you Peter, I agree and have already removed the insulation around the feed tube's fire bricks (see pic below) and have been contemplating replacing the bricks entirely with a formed pearlite/refractory mud but I believe I will build one of those slide dampers as described in the post JB linked to earlier. I will be shielding the feed tube from the radiant heat off the barrel seeing as it is so close and throws a substantial amount of heat at and into the feed.

JB: Funny you linked that post. I have read and re-read that one so many times. I am also listening to Paul's podcast 104 yet again. I wouldnt say Im addicted to the blower, I just prefer not to smoke out my whole house Yes, I will be screwing the duct together when I know they will not be moved again. Thats the same reason I am using the duct tape, it is temporary, I used 1/2 the roll of aluminum tape just to tear it off to rearrange the duct. Backfill the whole floor laid duct? Yes, I was going to wait until the unit performed well but it seems I should at least semi cover that section to help with the draft. I plan on having stone on each side and top of that run enough to support itself and anyone who steps on it to avoid collapsing.

Chris: WOO HOO is right! I am so thrilled to be seeing my heater begin life. I did fill in about 1/3 of the baffled mass from the ends. I intend on opening the lid and filling the rest with my densest materials. Do you think raising the exposed duct back to where I had it would be better than cobbing over it? Glad you enjoy the pics. I committed early on that I would document every detail I could in attempt to share and help as many others as possible as these forums have helped me generously and I know there are plenty who just love to follow these builds and see/read every little detail.

In summary: I will build a feed damper insert, finish filling my mass and cover over the floor laid duct.

Thank y'all again

OK, I would like some feedback/opinions on this. I have come to strongly believe today that my largest problem is with my exhaust draft, i.e. my chimney, or lack there of. Up until now I have not truly considered my house's specific needs to properly maximize draft. After reading the post "Is my barrel to small?" and the link that Peter mentions in the post:

Peter Berg wrote:

danny zeigler wrote:Are you saying that I have to build a vertical stack on the outside of the house up to the roof like with a wood stove?

Yes that's the picture. Read this artcle about the neutral pressure plain and other relatively unknown phenomenons. Especially the part after the header "Is Your House a Better Chimney Than Your Chimney?" That might be the problem in your situation.

RMH's burn tunnel sits 5 ft below ground. There are 2 stories and a full walk up attic above it with many upper story leaks. My house IS a better chimney than my chimney.

I now intend to tie into the basement base of a 5.5"x8.5" ID unused indoor brick chimney that exits my roof to peak height. This chimney drafts constantly as I have flame tested it on all 3 floors. This as opposed to my current configuration that back drafts excessive cold air when not being forced out by blower. I believe my NPP to be well up into my 1st floor and my basement negative pressure to be quite strong, more so than my RMH can overcome. Added bonus is that being that the brick chimney is indoors, it acts as more mass to be heated and radiate.

hey martin, what a nice surprise you have a chimney already! I can't think of any reason not to at least hook on to that thing, temporarily for testing if nothing else. Can you run your duct pipe near the 55g barrel, to pick-up some heat on the way to the chimney? Is the access to the chimney far away, or thru the floor? Is this the same chimney that is presently on your house furnace? I'd say 'go for it'.

james beam

james beam wrote:hey martin, what a nice surprise you have a chimney already! I can't think of any reason not to at least hook on to that thing, temporarily for testing if nothing else. Can you run your duct pipe near the 55g barrel, to pick-up some heat on the way to the chimney? Is the access to the chimney far away, or thru the floor? Is this the same chimney that is presently on your house furnace? I'd say 'go for it'.

james beam

Chimney is against the opposite wall from my RMH, i need to make a 30' run through another stone wall in place of my current 15' run from mass to foundation wall, so an added 15' of length before entering my 30' chimney. But hey, it already drafts so Im believing it will do the trick. It is not in use. My house has 3 chimneys, only 1 currently in use by the furnace, all structurally sound, leak free and self drafting. This one is roughly 6"x8" ID, indoors and made of brick, no flue/liner but has only ever been used by wood stoves; more specifically there used to be 2 kitchen wood stoves/ovens, one on the first floor and another on the second floor as back then this house had 2 kitchens. It used to be a boarding house when the Erie RR was king in town. The 2nd floor kitchen was private for the owner and the 1st floor kitchen was shared by boarders. Originally, the house had the same steam heat as it does now but with no boiler as it was fed by a main steam line that came from the boiler shops downtown, must have been quite the perk!

Hmmm......

Okay, I read the 'house is a chimney' article and I'm with you on the draft thing with the NPP and the size of your house... but your 5.5x8.5 chimney CSA (46.75) is smaller than your feed (49), and especially with such a long run-- although I suppose your NPP draft at the basement tap is the strongest and may overcome this difference.

So here's a suggestion: What if, after you tap into your basement chimney and you get such an amazing draft increase that your barrel temps jump 100 degrees, you then turn your old basement wall exhaust into your new sub-NPP cold air intake-- but don't duct it to the feed box; that would mess with your burn temps.. and don't just duct it into the basement; that would cool off your basement too much-- instead, duct it to blow across the barrel to increase the delta in your difference engine and heat the air as it enters the basement... you could put in a damper to control the flow. This may give your system the boost it needs to overcome the extra work of getting all the way across the basement.

I mean, since ya got the dang hole in the wall already... wot da heck, ya know?

Chris Burge wrote:Hmmm......

Okay, I read the 'house is a chimney' article and I'm with you on the draft thing with the NPP and the size of your house... but your 5.5x8.5 chimney CSA (46.75) is smaller than your feed (49), and especially with such a long run-- although I suppose your NPP draft at the basement tap is the strongest and may overcome this difference.

So here's a suggestion: What if, after you tap into your basement chimney and you get such an amazing draft increase that your barrel temps jump 100 degrees, you then turn your old basement wall exhaust into your new sub-NPP cold air intake-- but don't duct it to the feed box; that would mess with your burn temps.. and don't just duct it into the basement; that would cool off your basement too much-- instead, duct it to blow across the barrel to increase the delta in your difference engine and heat the air as it enters the basement... you could put in a damper to control the flow. This may give your system the boost it needs to overcome the extra work of getting all the way across the basement.

I mean, since ya got the dang hole in the wall already... wot da heck, ya know?

Lol, Chris, yea what the heck, right? I was thinking something of the sort. As far as the CSA, if people can exhaust an 8" heater with a 6" pipe just based on the right amount cooling, condensing and shrinking of the gasses then I think my reduction of 3"CSA after a 35' run (including 25' of 10" duct) should be pretty safe. Based on the chart and my exhaust temps between 100-200deg F, I expect between 20-35 Pa drawing up the chimney. That should be noteworthy.

hey martin, did you know I'm not an engineer! but I can recognize a beer bubble when I see one, hahaha, so....some pixs or diagram of the basic basement & chimney location & RMH location might help. As for the chimney, is it a straight shot up?, or maybe cuz ya had multiple stoves, on various floors there are some turns in the chimney? I'm alittle curious why ya didn't go for the chimney in the first place, would it be easier for you to use in the long run, to simply rebuild your RMH in the room with the chimney? Even tho you have built a nice stove as it is now, I would definitely go for more draft that the chimney offers. The thing about an already built chimney there is noncombustible air chamber around the outside of the existing flue pipe, so you probably won't realize any mass warming from the chimney exterior itself...I may be wrong about this. Back in the old days they may have used fire brick up against the liner for the whole thing, and didn't need that air space, way back when, definitely would be good to know if it will warm up as usable mass. I'm thinking lets say your exh. temp. as it enters the bottom of your chimney, if it was 120 degrees & steamy, it must rise IF connected to a 30' vertical chimney. Yanno most of your clay joint cement and other parts, like your baffles should be reclaimable into a new setup.

james beam

Well, I do believe we have gone done figured this thing out! I have never had such a good draft with no smoke back naturally aspirated. Definitely was a issue of negative pressure plane and it would only be overcome by a roof peak height chimney.
A SUPER HUGE THANKS TO ALL WHO POSTED FEEDBACK!
I would have probably given up without your support.
Now, brass tacks...

hey martin, did you know I'm not an engineer! but I can recognize a beer bubble when I see one, hahaha, so....some pixs or diagram of the basic basement & chimney location & RMH location might help. As for the chimney, is it a straight shot up?, or maybe cuz ya had multiple stoves, on various floors there are some turns in the chimney? I'm alittle curious why ya didn't go for the chimney in the first place, would it be easier for you to use in the long run, to simply rebuild your RMH in the room with the chimney? Even tho you have built a nice stove as it is now, I would definitely go for more draft that the chimney offers. The thing about an already built chimney there is noncombustible air chamber around the outside of the existing flue pipe, so you probably won't realize any mass warming from the chimney exterior itself...I may be wrong about this. Back in the old days they may have used fire brick up against the liner for the whole thing, and didn't need that air space, way back when, definitely would be good to know if it will warm up as usable mass. I'm thinking lets say your exh. temp. as it enters the bottom of your chimney, if it was 120 degrees & steamy, it must rise IF connected to a 30' vertical chimney. Yanno most of your clay joint cement and other parts, like your baffles should be reclaimable into a new setup.

james beam

2nd pic is for you, a quick basement diagram. Chimney is a straight shot up basement, 2 floors and an attic. It has a capped off port on each floor as it used to be active for two kitchens. It is a semi difficult reach, thus my avoidance. It has NO LINER. It is just a rectangular indoor single wall brick chimney, thus the extra mass idea. It drafts quite well as the new vid shows.
http://youtu.be/dnBYBfwhadc

BTW: her name is Hippie Heater

Next up will be a water heater to assist boiler temps.

I am interested in requests for pic, vids, experiments, whatever. Y'all have given me so much, I'd be happy to tickle yer fancy.

Hey Martin, Congratulations for the 'smog free' conversion of your old chimney/stove. Just think of the valuable environmental impact you're contributing, ~no petro fuel, ~very little wasted heat pollution, ~recycling scrap wood material, ~very little visible smoke pollution, ~no annoying fumes at ground level (your neighbors garage is now happy), ~enduring stove work (once you iron out all the kinks), ~high safety value in practice.

Would you consider stuffing some new 7" or 6" duct pipe down the chimney from the top? The reason I want a duct pipe flue liner is because the old chimney is possibly 100 YEAR OLD MORTAR, ~if it can leak, it will leak~ (you have said it is seal tested or safe, but that chimney is really old, structurally sound is great, but still might eventually leak wet creosote fumes or steam). I would want a chimney liner secured with screws at each joint & sealed with foil. A chimney liner doesn't have to be installed immediately, while testing, but moisture + old brickwork + freezing outside temps = chimney liner. I'm not sure you can deform a 7" duct pipe into an oval shape, to fit within your existing chimney, I would prefer 7" over the 6"...if possible. You might try asking your local 'heating & air conditioning business' if they have, or can make, an affordable rectangular metal lining that would fit your chimney. Since ya got a dead bird in your cleanout tray, you could make a course screen for your rain cap. ~~Just a thought.

Now that your temporarily plumbed into the chimney, do you eventually expect to bury your 30+ feet of duct pipe in mass, as you know the idea is to retain as much heat into the mass, and waste to the chimney what is left over. Do you eventually expect to move the stove into the other room, or perhaps you like the stove where it is under the 'new' part of the house, which I totally understand. I once had an old house with an addition, the addition was always the coldest part of that house. From your diagram, I would be very careful of the stone walls, they support the house, in many ways.

As for heating water, I'm thinking 'double J, double barrel'...hehehe, that is because YOU are doing all the work, so well! :)

Heyyyyyyyyyyy hows that peterchannel T you made working out? Can you confirm that with the peterchannel T, the fire doesn't burn vertical on your feed stock, or is it the proper draft of the chimney? Obviously your using the peterchannel T, so I'm guessing it is doing the trick! Now that you got your chimney working, how is your 'coals hole' working? With the peterchannel T in place, will you try rebuilding the insulation brick around the feed tube?, yanno just for kicks.

james beam

Martin,
I've come to understand you've got a p-channel in the feed. You mention in the vid the plate is hanging 1/4" into the tunnel. Have you thought about the 1/4" gap behind the plate as well? Thus the cooling of the first brick will be very much efficient and there's always some preheated air injected at that very important spot. The stove should be running cleaner with it, but it doesn't enhance the draft much.

james beam wrote:Hey Martin, Congratulations for the 'smog free' conversion of your old chimney/stove. Just think of the valuable environmental impact you're contributing, ~no petro fuel, ~very little wasted heat pollution, ~recycling scrap wood material, ~very little visible smoke pollution, ~no annoying fumes at ground level (your neighbors garage is now happy), ~enduring stove work (once you iron out all the kinks), ~high safety value in practice.

Thanks JB. It is almost euphoric to think about deeply. Especially knowing this is just the beginning of much more.

james beam wrote:Would you consider stuffing some new 7" or 6" duct pipe down the chimney from the top? The reason I want a duct pipe flue liner is because the old chimney is possibly 100 YEAR OLD MORTAR, ~if it can leak, it will leak~ (you have said it is seal tested or safe, but that chimney is really old, structurally sound is great, but still might eventually leak wet creosote fumes or steam). I would want a chimney liner secured with screws at each joint & sealed with foil. A chimney liner doesn't have to be installed immediately, while testing, but moisture + old brickwork + freezing outside temps = chimney liner. I'm not sure you can deform a 7" duct pipe into an oval shape, to fit within your existing chimney, I would prefer 7" over the 6"...if possible. You might try asking your local 'heating & air conditioning business' if they have, or can make, an affordable rectangular metal lining that would fit your chimney. Since ya got a dead bird in your cleanout tray, you could make a course screen for your rain cap. ~~Just a thought.

Yes, when finances permit, I would like to line the chimney. Rest assured, it is much newer than the rest of the house and the mortar is strong and holding well. As for the screen cap, I will when I feel balzy enough to toss a rope over the roof and climb up there.

james beam wrote:Now that your temporarily plumbed into the chimney, do you eventually expect to bury your 30+ feet of duct pipe in mass, as you know the idea is to retain as much heat into the mass, and waste to the chimney what is left over. Do you eventually expect to move the stove into the other room, or perhaps you like the stove where it is under the 'new' part of the house, which I totally understand. I once had an old house with an addition, the addition was always the coldest part of that house. From your diagram, I would be very careful of the stone walls, they support the house, in many ways.

Yes, I do plan on replacing the flex duct with 8" pipe buried level to the chimney once I remove some stone wall(s). I have been studying the house supports for some time as I plan to replace/rebuild several in attempt to level floors and create more basement space. This will be when I can bury a direct pipe to the chimney, effectively making the floor a very large thermal battery through the center of my house.

james beam wrote:As for heating water, I'm thinking 'double J, double barrel'...hehehe, that is because YOU are doing all the work, so well! :)

Nice! but I think I'll start with a coil of 3/4" copper tubing wrapped around my heat riser in a loop to my boiler (open loop)

james beam wrote:Heyyyyyyyyyyy hows that peterchannel T you made working out? Can you confirm that with the peterchannel T, the fire doesn't burn vertical on your feed stock, or is it the proper draft of the chimney? Obviously your using the peterchannel T, so I'm guessing it is doing the trick! Now that you got your chimney working, how is your 'coals hole' working? With the peterchannel T in place, will you try rebuilding the insulation brick around the feed tube?, yanno just for kicks.

I have yet to do comparison burns w/ and w/out the peter channel T so I really can't say just yet. I would bet the strong draft is the main fix here though. The ash pit seems to be working quite well with a proper draft and burns down to super fine ash but does hold hot coals longer; which is an added bonus to helping re-light another burn ;) If I do rebuild my feed, I am leaning towards a system like Rob has on his: https://permies.com/t/18515/stoves/Burning-Pellets-Rocket-Mass-Heater

Thanks again JB and Merry Christmas to you too :)

Peter Berg wrote:Martin,
I've come to understand you've got a p-channel in the feed. You mention in the vid the plate is hanging 1/4" into the tunnel. Have you thought about the 1/4" gap behind the plate as well? Thus the cooling of the first brick will be very much efficient and there's always some preheated air injected at that very important spot. The stove should be running cleaner with it, but it doesn't enhance the draft much.

Yes Peter, thanks for noting that. I have placed it 1/4" away from the tunnel brick and it hangs 1/4" lower than the tunnel ceiling. I do believe it runs cleaner now as I actually opened the "dummy" pipe for a second and had no smoke or stink. I will be getting a laser temp gun soon to get hard numbers on the subject.

where are the discussions about bypass vents?
will i be saying 'duh' soon?

clem nelson wrote: bypass vents?

bypass vents?

I just wanted to say that I've been lurking on this thread the entire time and I have learned so much!!

Martin, Any updates on your stove? We are entering a new heating season. I've been wondering how your system performed for the balance of last season. Hope all is well!

Colin

Martin Seidel wrote:[color=blue]Ok, let me just start by thanking every ingenious one of you for all your hard work and generous teachings; especially Ernie & Erica Wisner and Paul Wheaton, you are true pioneers and have shared so much that I am grateful for.

Erica and Ernie and Paul have done wonders to develop and popularize rocket stoves and RMHs.  As has Uncle Mud.

We need to remember Ianto Evans as one of if not the originator of the rocket stove and the J tube stove, and the Lorena stove.

And while we remember Ianto, he also reintroduced cob, an ancient and traditional building material.  He and Linda Smiley with a third individual started the Cob Cottage Company in Cottage Grove (or somewhere) in Oregon.