• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • paul wheaton
  • Mike Jay
  • Anne Miller
  • Jocelyn Campbell
stewards:
  • Devaka Cooray
  • Joseph Lofthouse
  • Burra Maluca
garden masters:
  • Dave Burton
  • Pearl Sutton
gardeners:
  • James Freyr
  • Joylynn Hardesty
  • Daron Williams

Rocket stoves in Greenhouses , our own forum topic  RSS feed

 
Posts: 24
Location: Butte County Idaho zone 4 but more like zone 3 Lots of wind and average of 8-9 inches ann. precip.
1
food preservation forest garden greening the desert
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

thomas rubino wrote:Hi Dina;  Possibly the book you are referring to is the original Rocket mass heater book by Ianto Evans  & Linda Jackson. For years this was the RMH book of choice. Its still a good choice for backround.
There is now a newer option called the RMH Builders guide by Ernie & Erica Wisner.  This book is now the RMH go to book for accomplished builders and first timers.
My green house in northern montana has an 8" J tube and uses less than 5 cords all winter to keep it 40-70 all day and all night with NO FIRE from 10 pm -6 am .... pretty neat huh.
If you are just learning about RMH's be prepared to get the bug ... you'll be up half the night reading ... and soon .... you'll want to become a rocket scientist yourself!
ENJOY !



Awesome! Thank you! I would LOVE a visit to see how you have things set up and operating! There is so much to read and so many different ways to 'skin this proverbial cat' depending on materials on hand and location on the planet and all that changes with that pinpoint that my head doesn't seem to stop spinning!
 
gardener
Posts: 1914
Location: latitude 47 N.W. montana zone 6A
215
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Sounds to me Dina, that you have caught the BUG!!!  OH NO, No hope for you ....  Now you will have to build a RMH!!  
Looks like your down in the Salmon area.  To get up to where we are, its a long haul up US 93 . You would be passing numerous RMH's some with greenhouses , including the Wheaton ranch. We are 2 hrs NW of Missoula.
Our greenhouse is actually an artists studio now with nothing edible growing (unless you count the coffee & lemon tree... err bushes.)  
We did start out as a working greenhouse but my wife is now more interested in her art than a year round garden.
Visitor's who want to talk rocket science are always welcome.  
R-86_01.JPG
[Thumbnail for R-86_01.JPG]
studio / greenhouse
greenhouse-5.JPG
[Thumbnail for greenhouse-5.JPG]
humble beginnings
DSCN1027.JPG
[Thumbnail for DSCN1027.JPG]
danger artist at work
 
master steward
Posts: 3356
Location: Northern WI (zone 4)
739
books food preservation hunting solar trees woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I haven't really paid much attention to the rocket options for greenhouses.  But now that I'm building a greenhouse, I should keep it in mind if my initial heat source fails me (compost).  

Is there a mass heater for a green house that you can load a bunch of wood into once or maybe twice a day and that's it?  I don't want to be tending a little fire for an hour+, I want to get a larger firebox burning and let it convert that wood into heat that lasts all night (and day).  
 
thomas rubino
gardener
Posts: 1914
Location: latitude 47 N.W. montana zone 6A
215
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Mike;
Your asking for a lot... In an insulated home 2 fires a day is plenty , in an uninsulated greenhouse... that really won't cut it in winter.  RMH Jtubes burn 45-60 minutes , batchbox rmh they say burn 60 minutes but at a hotter rate.   If you want a mass in a greenhouse to stay warm overnight in a northern climate it has to burn the better part of the day.  Its really not that hard to set a timer for 45 minutes and pop over to stuff more wood in the dragon.  
 
Mike Jay
master steward
Posts: 3356
Location: Northern WI (zone 4)
739
books food preservation hunting solar trees woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I know, I like to ask for a lot.  Luckily my greenhouse will be insulated and passive solar with nighttime deploying insulation for the glazing.  I think it will be able to keep itself warm during the day with the sun, I'm just trying to get it through the night.

So "batch box" sounds like what I'm talking about right?  A batch of wood?  Versus little splits and twigs?

According to my crude thermodynamics, my greenhouse will theoretically lose 345KBTU per day maintaining a 60 degree difference to the outside.  On an "average" day in December it will receive 483KBTU of solar energy.  So if I have a day with half the gain of average, I'd be short 100KBTU.  If wood is 7KBTU per lb, and if I could convert 14 lbs of wood perfectly into heat, I'd be all set.  So a batch that holds 25 lbs of wood could do the trick.  Unless I'm way off on the math or overly optimistic (which I often am).
 
thomas rubino
gardener
Posts: 1914
Location: latitude 47 N.W. montana zone 6A
215
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Always good to be optimistic !  I like the sound of your greenhouse. Is that automatic deploying or manual on the glazing insulation ? I hope you post photo's ,Would be nice to see your build.
Yes, a batch box holds its wood horizontal,uses split,but larger wood and more of it than a J tube. It is also a closed unit with no sparks able to get out.
Peter van den Berg has been making some really nice units.  There seem to be new innovations in design every few months.
A batch box with  brick bells  would have a smaller footprint than a long low mass. Might be something to investigate.
Seems like northern Wisconsin would get mighty cold in December. Also seems your predicted solar gain might be a smidgen overly optimistic for that time of year ??? :) We have clouds and snow or snow and clouds at that time of year.
We love our rmh in the studio / greenhouse , it is evenly warm thru the whole building, not the typical hot by the stove and freezing by the wall wood stove effect.  Of course going from 12 plus cords to less than 5 sure helps.
 
Mike Jay
master steward
Posts: 3356
Location: Northern WI (zone 4)
739
books food preservation hunting solar trees woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
My plan is for manually deploying insulation at first so I can "feel" for issues as it goes up and down.  Then once I get sick of doing it manually I'll put a motor on it.  I've been documenting the design and build in this thread: Mike's Passive Solar Greenhouse Design/Build  The thread is rather long but now I'm building and there are pictures to look at.  Design chatter is mainly on the first page but I've evolved the shape a bit over the last year.

Yup, it gets rather cold here in December.  Jan/Feb is worse but it's sunnier then.  Mid Nov through Mid Jan is my challenge due to cloudiness.  My calculated solar gain is from a few online sources but the data is hard to really understand.  They list things like "average" and "average minimum".  I really want to know what the worst day is, the 5th percentile, etc so I can predict better.  Oh well...

Thanks for the batch box info and the brick bell option.  Hopefully my compost will work but if not, now I know where to begin my RMH research.  Thanks!
 
Dina Johnson
Posts: 24
Location: Butte County Idaho zone 4 but more like zone 3 Lots of wind and average of 8-9 inches ann. precip.
1
food preservation forest garden greening the desert
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

thomas rubino wrote:Sounds to me Dina, that you have caught the BUG!!!  OH NO, No hope for you ....  Now you will have to build a RMH!!  
Looks like your down in the Salmon area.  To get up to where we are, its a long haul up US 93 . You would be passing numerous RMH's some with greenhouses , including the Wheaton ranch. We are 2 hrs NW of Missoula.
Our greenhouse is actually an artists studio now with nothing edible growing (unless you count the coffee & lemon tree... err bushes.)  
We did start out as a working greenhouse but my wife is now more interested in her art than a year round garden.
Visitor's who want to talk rocket science are always welcome.  



I would love a road trip with many stops along the way! I am located in Arco Idaho...

I just got back from a dog rescue run to Dillon Montana on Monday and had a lovely experience with a flat tire on a back mountain road on my way home. I was able to see a lot of elk bedded down while finding my 'center' and strength to break the lug nuts loose and change the tire to an old donut and drive ever so slowly BACK to Dillon (I only managed 'slow' on the gravel but once the pavement was under the rubber, desperation kicked in to get to a tire shop before they closed) I was unfamiliar with that area between Grant Montana and Leadore Idaho... I am ready to take that road again with my new tires! Maybe I can get a critter sitter for a long weekend so the husband can tag along, maybe mid October. We need to get our chicken coop winter ready and our high tunnel finished before it cools off too much...


Would ya happen to know anybody in my area willing to help out with building the end walls and draping the double plastic over the 24Wx88L ribs??
 
Posts: 14
Location: Latvia
forest garden goat tiny house
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Rocketeers,

short but important question about the draft of a Rocket in a Huge !!! Greenhouse

I have already build 16 RMH before I build my 2 last ones I have the question on. I also have books and DVD´s and so on but no Answer so far on the following question:
We have a greenhouse  10 meter wide and 50 meter long. In the middle I have build 2RMH


The Rockets are build in the middle so each pipe in the ground is approx 30....32 meter long including the chimney outside. The dimensions of the tummel, heat riser, .... is the same like always.
But I get NO draft to the Rocket.  Sometime the Smoke sucked in, some time the flame comes out  of the feeding mouth, some times the fire went even out because of a lot of smoke
The barrel becomes warm but not hot.
It seems because of the big cold system i can get no draft in, even after some hours of heating up the system.
Is this system to long (30 m horizontal pipe in the ground)??  

Thanks for help in advance
 
thomas rubino
gardener
Posts: 1914
Location: latitude 47 N.W. montana zone 6A
215
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Thomas; Your trying to push almost twice the distance an 8" rocket can push.    
Max run for an 8" is 50' or 15 meters.
 
gardener
Posts: 640
Location: +52° 1' 47.40", +4° 22' 57.80"
72
rocket stoves wood heat woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Not to mention the horizontal pipes in the soil, when there's no insulation beneath it the ground below acts as a giant heat sink.
 
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hey folks!

You guys are awesome!

I have a little different perspective maybe as a 20-something interested in commercial aquaponic greenhouse production using zipgrow towers. For those who aren't familiar that means my plants won't be in the soil or what you all seem to be using for your mass. Instead they'll be hanging in fiber media towers with water from the sump tank trickling through them.

I am in the planning stage of my system and I am planning to start small and scale quickly.

For context I am in zone 4 south central Missouri with an altitude of approx 1750ft. I obviously won't need the stove year round but would like to keep up production through the winter. I may even eventually choose to supplement light for some plants like basil.

I tried to read this thread front to back and just couldn't get through it all so I apologize if I have missed the answers to some of my questions.

Firstly I'm not sure if anyone answered the humidity problem for the cob? I was thinking you'd have to fire the thing up and dry it out before you started growing and building up humidity in the greenhouse, then once dry paint the cob with whatever that seal is they use for pottery.

Now here's where the eyes will start to roll because I will need to heat the air. My plants will be hanging in it. I was actually looking into wood burning boilers before I stumbled upon what this community here has been up to with the rocket stoves.
Here's a quick look at how those wood burning boilers work with heat exchanges to warm the air: https://youtu.be/SRuCzKal0o8?t=108
Note the water does not actually reach boiling temp in these systems.
So that would be great but its such a huge upfront cost obviously.
I know I'm hitting some touchy ground here but I have to ask if anyone has figured a way to make essentially a rocket boiler (that doesn't actually boil).

I saw a video where Earnie was talking about the temperature differences in different parts of the system as related to the distance from the top of the barrel down to the top of the shaft coming off of the burn chamber. Could that distance be increased so as to keep the top of the barrel at a mere 200 degrees so that another barrel of equal size could be set on it filled with water that never actually boils but circulates to heat exchanges? I was thinking that instead of a bench to each side of the burn chamber you could have more barrels where heat is pooling and heating water barrels above them. On these secondary barrels over heating should be less of an issue and maybe they could be insulated on the sides so that their heat is more efficiently directed upward into the water.

I know feeding the rocket stove is also an issue, and I have seen Rob's pellet feeder. I love that Idea but I also have to wonder if rocket stoves can be scaled up to accommodate larger loads that burn for longer.

Many of you maybe thinking at this point that I need a different solution. I have to say the thing that draws me most to the rocket stove is that it burns away the smoke! With the addition of a dehumidifier you could just let the exhaust come out inside of the greenhouse and you would be supplementing CO2 for your plants! (not to mention you're wasting none of the heat you are producing) That is one less limit on your plants growth and because the plants are getting a more efficient "breath" they will open up their "mouths" less and therefor slow the transmission of plant diseases.
here's a far more educated guy than me going on about it:  https://youtu.be/xgLGCH9ErVE

I think that covers my questions and ideas on the subject. I know that was a lot, feel free to pick it apart. I appreciate your input!
 
Posts: 409
Location: Wellington, New Zealand
12
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Exhausting carbon monoxide into the greenhouse makes for a short life.

Exhausting carbon dioxide into the greenhouse is futile unless you first provide adequate light levels as it only works when carbon dioxide is the limiting growth factor, eg. In summer.
 
thomas rubino
gardener
Posts: 1914
Location: latitude 47 N.W. montana zone 6A
215
cat pig rocket stoves
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Jay;
I hardly know where to start.    Graham already answered about venting exhaust into your green house, lets just say ,not a good idea.

Next lets talk about boiling water...  https://www.youtube.com/watch?v=1oDpmmsqHwQ This is a safe way to make hot water with a rmh.  https://permaculturenews.org/2012/11/23/rocket-stove-hot-water/

Giving  a larger gap to the riser would lower the barrel top temperature yes,  but trying to set another barrel on top would steal to much heat and cause an incomplete burn.
You could try hanging a barrel above your hot barrel but not touching. Would certainly warm up, without taking to much heat away from the burn.

Cob and humidity.   Yes, you must allow your cob to dry, and heat up. This can take 4-6 weeks or more. Thing is , depending on what style you build, you may not have huge amounts of cob to dry.  Using a brick containment or  building a Matt Walker 1/2 barrel bench in a containment , Masonry bells , there are options other than an all  cob seating bench.

Longer burn times .   A warm  8" J tube needs wood apx every 45 minutes.  an 8" batchbox might go hour and 15 maybe 1.5 but no more.  You can build larger ones they say.

We heat a solex covered greenhouse in northern Montana with an 8" J tube. Fire is burning all day until 8-9 pm then no fire all night long. commonly +10 - 20 outside and 40 - 50  inside next morning
R-39_01.JPG
[Thumbnail for R-39_01.JPG]
brick contained mass
DSCN1027.JPG
[Thumbnail for DSCN1027.JPG]
greenhouse rmh
 
Jay Gore
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Grahm, Hi Thomas,

I was under the impression all the carbon monoxide burns off. I guess I should have assumed the science on that isn't an exact one. Has anyone held a carbon monoxide detector up near one of these things to test what's going on there? I do hope one day to supplement light when necessary and that is when carbon will become the limiter.

This coming year I'm starting so small I will just utilize the warmer months then hope to move into a bigger greenhouse with adjoined fish house and the works next winter.  I'm sort of feeling out the feasibility of the RMH for that project and how I can grow from there with it. I'm thinking feeding the thing all day I could handle one day.. after I quit my day job and build a WOFATI!

I hadn't thought of the heat being stolen and messing up the burn. I'll definitely get to those links on heating water here in a couple hours and keep thinking about it.

Thanks for your time guys. I know I'm kind of the lunatic late to the party already drunk here.
 
Mike Jay
master steward
Posts: 3356
Location: Northern WI (zone 4)
739
books food preservation hunting solar trees woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Jay Gore wrote:For context I am in zone 4 south central Missouri with an altitude of approx 1750ft.

 I don't want to take the thread off track but I just wanted to check this detail.  I think south central Missouri is closer to a zone 6.

Also, along a tangent...  How are you designing the greenhouse?  Passive solar designs and insulating the foundation can make a huge difference in how much heat you'll need to create.  May be worth another thread so that it doesn't take this one too far away from RMHs.
 
Jay Gore
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hey Mike!

You are right! I just did a quick image search for zone maps and whatever I was looking at was not the USDA system because it was going the opposite direction! I'm right at the border of 6a and 6b.

I'm going to be in crumby little tents for a while. I'm thinking if I just keep the water livable for the fish, grow something crazy hearty like tatsoi and not worry about air temp during the winter I might be able to keep it going year round in these smaller stages. When I scale up serious I'm leaning towards a walipini! That should make the RMH far more feasible! I've been up all night researching! SO MUCH COFFEE! I was working on this earlier... er.. sometime:
https://www.instagram.com/p/Br-UXVTlNn7/
 
gardener
Posts: 2863
Location: Upstate NY, zone 5
122
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I think a water tank on top of the regular barrel would not affect the burn in the riser at all, but would cool the exhaust gases more than a plain barrel, increasing the downdraft effect if anything. I would give a good gap from the riser top, several inches at least, but all combustion should be done once the gases exit the riser if the core is well built with a tall enough riser.

CO should be very low in a well-functioning RMH, but at start and coaling stage at the end of a burn it will be higher, and if conditions are not good it might become an issue at other times. Best not to take a chance.
 
Glenn Herbert
gardener
Posts: 2863
Location: Upstate NY, zone 5
122
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Re climate zones, I knew that the USDA growing zones and the heating zones went in opposite directions, but when I looked, I found three different heating zone systems in a quick glance, so my part of NY would be zone 5, 6, or 1, depending on which one you use, while I am in USDA zone 5b.
https://www.inchcalculator.com/calculate-many-btus-needed-heat-home/
https://basc.pnnl.gov/images/iecc-climate-zone-map
https://www.eia.gov/consumption/residential/maps.php

https://planthardiness.ars.usda.gov/PHZMWeb/
 
Posts: 1
Location: Nova Scotia, Canada
homestead solar woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi all,

First time to the group and hoping someone can help me wade through the mass of posts in this thread and elsewhere to ferret out the gems - my eyes have gone buggy reading over the past two days. I have Ernie and Erica Wisner's RMH design information, which it seems is the most current design information (??), but that doesn't cover greenhouse issues.

I am researching options to add heat to a walipini design planned for Nova Scotia Canada (Zone 6a - can hit -10 F / -25 C) rough image of the planned cross-section attached. The footprint is only 10' N-S by 16' E-W (i.e. windows face almost due south). The design _should_ stay warm enough for cold-season veggies without any active heating, but we are hoping to push it a bit more and I would like a contingency plan.

A RMH looks like a nice option, but there were also a lot of concerns posted about cob and humidity - maybe those are dead now? I want to be careful to design it to not overheat the small space while allowing for a slow release overnight. I will only be able to tend a fire in the evenings and maybe a short burn in the AM. I don't want to give up too much growing space - hopefully not asking for too much.

My first thought was to put the long pipe and cob "bench" under a raised bed at the back, but it looks like moisture might be an issue. I like the idea of using water for heat storage - are there any gems for a good manifold design to support this or could you just put the water jugs on the bench?

I'm happy to read and research, but I'm hoping that someone can give me some quick pointers to the most relevant content. Thanks in advance.
Wallipini.png
[Thumbnail for Wallipini.png]
Cross section of the initial plan.
 
Posts: 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi my name is Shiloh. I have a few questions. We want to build a thermal mass rocket stove for our aquaponic greenhouse. It is 72x30 ft and has media beds that run 58ft long. Our desire in to put the chimney/ thermal mass bench  under the media beds. The trick is there is not a lot of room under there. We have chosen to use 4 inch double insulated pipe because of space limitations and can only put 3-4 inches of cob on top of the channel. The channel is made of cinder blocks and filled with gravel, then the cob. This will leave about 3 inches before reaching the bottom of the media beds. My question is  Is that enough space and mass to not melt my beds. Another concern is am I going to need a S formation for the exsaust coming from the barrel to cool down the air flow before it goes under the beds.
thanks for any help.
 
pollinator
Posts: 2230
Location: Cincinnati, Ohio,Price Hill 45205
128
forest garden trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I'm no expert.
I think single walled duct is better for heating a bench.
Double walled would be right for the vertical chimney.
Using all cob will save money and deal the duct better.
If you are going to stick with gravel,  uninsulated  single wall stove ipe is recommended.

One single 58' stretch seems to be push the boundaries of what an 8" j rocket is capable of.
 
Why should I lose weight? They make bigger overalls. And they sure don't make overalls for tiny ads:
100 Chestnut Trees for 299$ or 50 for 195$ + Free Shipping & more
https://permies.com/t/107180/Chestnut-Trees-Free-Shipping-Interwoven
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!