Rocket stoves in Greenhouses , our own forum topic

I have not had the time to read into the full explanation on the rocket mass heaters. However, I have watched all of Paul's videos, read an article he made, and heard him speaking about the fluid dynamics and such several times in his podcasts. So I know enough to say that I def. don't know enough. lol

I agree that the wood stove in the video link has no rocket feature in it and therefore should probably be dubbed wood stove instead of rocket stove. It just burns hot enough not to smoke much.

I hypothesize that with a metal fuel feeder like in the tikki stove pic... that if it were made of something like aluminum that transfers heat almost instantly... the air feeding in from underneath should be pre-heated to very high temps before entering the burn chamber. This would(if it were to work) enable a hotter fire and a little more efficiency.

Then of course adding things along the chimney path would add the turbulence that can both create a cleaner burn and slow the exhaust down enough to enable some heat to be absorbed into the chimney.

Having the copper coil buried inside the mass of the stove would enable it some protection from the extreme heat and still allow it to slowly absorb heat well after the fire is out. I also suspect that vapor lock would be harder to achieve on a larger tube like that. I would have to research that one or just build it and see if it works.

Having a longer chimney would likely add more pull and violence to the burn chamber. Likely increasing temps. since the fire would be burning faster.

Perhaps lining the inside of the stove with something like this stuff rated at 2200deg F would be possible and give the system what it needs. It would double the price of the stove... but still very affordable.
http://www.amazon.com/Rutland-12-5-lbs-Castable-Cement/dp/B000H5T5EA/ref=sr_1_1?ie=UTF8&qid=1406309930&sr=8-1&keywords=chimney+clay

I want to first just make a simple tikki rocket stove for the porch both for practice and to give the kids a place to make smores without burning an entire fire pit worth of wood to do so. Less maintenance too.


Thanks for that reference! I need to read up on this stuff some time. It is surely very interesting tech. Maybe this Winter I will have time.

Here is a link to a Geoff Lawton vid on a rocket stove water heater. Seems even more efficient than the other one I was talking about earlier. A lot more complicated though... and a Lot more dangerous. He says they burn from between 800deg C to 100deg cC


Here is a link to the melting points of different metals.
http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html

Copper = 1983 deg F or 1084 deg Celsius ,which means it could melt unless protected from the immediate heat... and/or filled with water that is circulating.
Aluminum = 1220 deg F or 660 deg C
Stainless Steel = 2750 deg F or 1510 deg C

That means I would have to make the wood feeder out of a scrap piece of stainless since the aluminum would melt. I would have to make the internal fins out of stainless as well.

Bump Big AL

Hi! Newbie here, looking for help and information. I've already learned so much reading these forums, and you folks have given us the inspiration to proceed.
We have a 26' x 96' hoop house that we are converting to an aquaponic greenhouse. We'll have double layer poly, and the first 12' x 26' will be a cement pad to hold the fish tanks. We are hoping to use year round. When looking for heating methods, we started reading more and more about RMHs, but I'm confused as to where in the "tunnel" to locate it. Should I build it right on the concrete pad and do a straight run? (That's a LONG distance to go!) Or build in the middle of the tunnel and straight run out the North wall (over the concrete pad)? Or what? I'm comfortable with a large cob bench in the middle, but how much area will it heat and where should i run my flue? This is a plastic covered hoop - with only the end walls as solid material (N wall is plywood, S is polycarb panels). Suggestions? Comments? Help?

My first post -- but been reading Permies.com for about a year.

I'm ready to start building an RMH in my garage-converted-to-greenhouse and cannot get a response from Erica W. about which plan to buy. I'm providing photos which show 1)how we glass blocked in the garage door opening, 2) the layout of the greenhouse setup as currently conceived, and 3) the photo of the RMH that was posted on Ernie and Erica's blog Sept. 21 under the heading "Rockets in Montana" (apparently the RMH built at the recent workshop).

That particular photo is the "picture" I have in my mind of what I want to have in my "garage to greenhouse".

All I need to know is which of Ernie and Erica's plans I should use to get the design I want.

Thanks, in advance, for any assistance -- it's getting cold here in the Michigan UP, and I gotta get started !

Marci and Michael : A Big Welcome to Permies.com,our sister site Richsoil.com,and the Rocket + Wood Stove Forum/Threads !

Marci Location Please, I can not tell you if you will be able to close off the end w/ the Aquaponics and get enough heat for your winter without
an idea of your climate, However after we get past the colder part of the winter, you should gain3-4 weeks at both ends of your Growing
Season! Though you may be dependent on fans and crop covers at the extreme ends !

Pictures and location and then lots more help Big AL

My location is Central PA. It gets pretty cold here. I don't have any pictures yet - I will get some tomorrow of the high tunnel. Right now it is full of tomatoes. We've used it to extend our season for several years now (we grow commercially). But have never tried heating it through the winter.

Michael R. : I was called away and just now got off the phone, family issues ! You should be able to do a 6''system, with about 25 feet of pipe, What is the floor
in your 'Greenhouse', and what kind of construction and materials go into Your common wall with the house (Your Eastern Wall? ) ? Is there a height difference
between the G'house and Your Home !

If possible the best location would be with your Rocket Mass Heater's RMHs Feed Tube inside the northeast corner of your G'house this will make both tending
to your RMH and keeping the area picked up and clean as any wood brought in from the Outdoor Covered Storage Area will be right where it is needed, rather
than Your initial choice.

Your horizontal pipe can meet the 1st clean out 'T,' running south about 12 feet through your thermal mass meet an elbow and a 2nd clean out 'T" and an elbow
and now being much cooler, run back north on the inside of the 1st run, along the G'Houses east wall ! then a final chimney and up through the roof.

This is of course just one option, and others can be weighed and considered I want to make a suggestion based on the location I gave you, believing that you will
have some issues with protecting the exposures from heat along the G'houses eastern wall which I believe is Your common wall with your house !

I want to send you to :::--> Villagevideo.org/store, while there find, and clickon the You tube Icon on the right side of that page

At the next page you will find sets of short video clips arranged in playlist groups. Find the top one and hover your Mouses Icon just to the right of the word phrase

Rocket Mass Heater Scenes , Find and click on the [>PLAY] box!

This will allow you to run in order about 3/8th of a professionally done DVD of one of E & Es best builds, this build deals very well with protecting the common walls
exposures and gives you a dual use bench Safely !

I am not E &Es Social Secretary, they have been off playing with Wizards and Pyronauts Working hard at an innovators 'gather' and will probably
need some recovery time before resuming their burdens,but try again any way ernieanderica.info/shop For the good of the Craft! Big AL

Marci : You are going to need the 8'' system and should look into a Top loading J-tube Batchbox style Rocket mass heat that will be able to handle the load and give you a
cushion !

When you say Aquaponic do you Mean with, or without fish (and worms?)?just to make sure we are on the same page.

As I am going to send you off to you-tube land to look at a specific site, thesis where I warn you that there is a lot of CRAP on U-Tube, please use a very critical eye when
viewing Anything on you tube. Usually it is best to only go there on someones recommendation !

At You Tube type Bigelow Brook farm into the search field ! While I am sending you there to look at his Aquaponic set-up, and his RMH layout is hard to duplicate.
It is a good site. There is also a blog/store and he sometimes posts things to Permies.com.

I would be temped to put the aquaponic section in the center of you hoop house giving you two large Wind brake/air locks before entering your heated area ! As you enter
your regular (extended) growing season it would be easier to use fans to transfer heat to ether end of the green house from your middleThis also gives you a place to store
your dry fine split wood where it is close to where it is needed but out of the higher humidity of the heated wet area !

As your Exhaust gas temperature at the base of your final vertical Chimney will be about 150 degrees F going up through your Hoop house will not be bothered by the
temperature of the pipe, we do have people who have done this ! Again this is just a suggestion,the final call is yours we are just here to bounce ideas off of and soak up
a few ideas that your Fellow Members can pass on ! For the good of the Crafts ! Big AL

Al, by aquaponics, I mean fish with vegetables. I currently have two 300 gallon tanks (IBCs) with tilapia in them, and plan to get more. I will be setting up a combined system with primarily deep water raft systems (3 - 20ft x 3ft), and a few grow beds filled with media. (My prior system was much smaller, but we did well, and now i've inherited the high tunnel. ) For the RMH, I've read Ianto's book - but am not sure what you mean by a "J-Channel". I searched it on permies, and ... wow! It looks really big. The bigger BTUs sounds good, but i'm concerned with the height. The high tunnel is 13 ft. high.

On the J-Channel type, is there also a bench for thermal mass?

Marci : One of Ianto Evans earliest contributions to the long list of the ongoing development of all Rocket Mass Heaters RMHs, was to change from a horizontally fed
rocket that needed the operator there to constantly feed the small sticks into burn tunnel, to the greatly improved J-Bend that continuously fed the wood vertically
down through the Feed Tube into the Burn Tunnel, what you want is what you've got ! Thermal mass definitely how about under your tanks ? Or Bells ? maybe

While the whole Burner Base with the Heat Riser and the Barrel sitting above it should be less the 60'' tall, you probably will need a heat deflector above Your RMH,
and perhaps a dedicated fan! This is a detail to be worked out correctly for your installation and not a problem ! Your fellow Members have solved this problem before

The Batch loading system which is a newer wrinkle will generate even more heat by simply burning more wood at one time with the high temperatures and clean high
efficiencies expected of all Rockets but Would need almost another 40''(?) !

I must tell you that this is not an area I have worked in, but we will find someone to determine if this can be configured to be practical for You!

I hope you enjoyed your quick look at Bigelow Brook Farm, you could spend days in there learning something new every time !

I want to see Your Thoughts on placing Your fish tanks, and your rocket within the center of your hoop house to increase the dead air spaces and what you can do to
reduce your heat energy loss when we get the Arctic clippers and warmth is more important than sunshine ! For the good of the Crafts ! Big AL

Al, I've been a subscriber to the Bigelow Brooks Farm YouTube channel for awhile now - so many fascinating inventions! In fact, after i successfully ran my aquaponics for awhile, my original plan was to do a geodesic dome (I wanted to copy Rob's everything!) - but then our plans changed and I was given the high tunnel. I am still reading much about the J-channel, but haven't quite wrapped my head around it yet. I had already started gathering "stuff" for the RMH - so I have an 8" heavy metal pipe and access to as many fire bricks AND red bricks as needed (thanks to a friend who used to work for a brick yard - he's been storing them in his garage.) and about 6 - 55 gal. drums. Fortunately, my husband is a tool-maker and one son a welder, so I'm sure I can get one of them to weld the drums together for me or whatever needs doing. But I have to be able to tell them what I need done as they have their own projects going on. Can't someone just make me an instruction list, and say "do this first, then this....".
As for going under the fish tanks, my tanks will be sitting on a concrete pad. Should I run the exhaust under the concrete? We were picking and packing this morning, so I didn't get a chance to do pictures - but if you can picture a 26 ft. wide hoop house, 96 ft. long, the first 12 feet in length on the N (ish) end will be a concrete pad. That end will be closed in with a plywood/insulated wall with a door. (The concrete is not in place yet, so if I'm going to run heat under it, I need to decide that prior to ordering the concrete.) The only thing on the concrete will be my fish tanks and filters. Along the left hand side, past the concrete end, I will have 3 ft x 60 ft of 18" deep water "tanks" (really just concrete blocks covered with Dura-Skrim) on which my rafts will float. Depending on where I put the RMH and how much room I need for it, I could do more of these beds as lettuce and kale are our primary production crops. Along the left side (which is the wind/coldest side) I had planned to run a row of straw bales for insulation, and then to have my grow beds (expanded shale, hopefully), the total of which will take up approx. 30 ft in length and 6 feet in width. These plans are all I've gotten so far, and are based more on production needs than anything else. That leaves me a lot of space for playing around! Maybe I should section off the end? The far end - which would be South to South West - is polycarbonate panels with a door. The existing plastic (now 5 years old) will be taken off the entire tunnel, and i'll be replacing it with a layer of 6 mil IR poly and a second layer of 6 mil, with one of those little pump thingys inflating the air in between. The tunnel is designed to have roll up sides, but obviously for the winter i won't be doing that. I have thought about some pop-can solar collectors on the south end as well - that end is the furthest from my fish. I will have electricity available for my tanks, air supplies, pump, etc., but really don't want to depend on it for heat. Yes, fans are a must - my youngest son has been studying quite a bit about air-flow dynamics in a greenhouse and he said I must have fans. I said, "Yes, Sir!" I haven't even settled on my "floor" yet as right now there are still tomatoes growing in the high tunnel. The tomatoes are coming out this weekend so we can get moving. But I'm thinking my flooring choice can help with heat as well. Anyhow, those are my thoughts. Much to do - and appreciate any thoughts and suggestions.

Marci : Don't be shy, you're among friends let it all out O.K. Now lets see what we can do ! I am trying to sketch out what I have learned
and I really am doing it your way! I just need time to understand, redraw and re-interpret!

1 ) You need to have a thermal break/insulation between your outside walls and ether the Cement slab or the Earth around a buried horizontal chimney
Thermal mass. you are also going to need a thermal break between the Thermal mass and the Chimney or you will be surrendering much of the heat
energy you hope to store within the thermal mass !

Because you have told me that your long axis of your hope house runs North South I understand that anything you place south of the far North end of the
tunnel will Screen or sun-block that space ! Therefor as a heat conservation mode you must have an air lock on the far north end ! This is still a good place
to have an area for dry wood storage as other wise you are going to be opening And passing through two doors while your arms are loaded with wood !

Stacking wood within a heated and humid space is an exercise in failure, your only remaining option is an exterior wood box penetrating both layers of the
outside skin of your hoop house, with the wood loaded from the outside then repeatedly resealed after loading. This is followed by the need to reach into
the woodbox from the inside, remove the stacked wood and then reseal the woodboxes inside door seal !

This is why I recommend a roomy airlock at one end of the aquaponic room, the extreme northern end works well with the picture? I have in my mind!
Initially I would consider the heavy weight 8'' pipe to be good trading material, we will not be using it in the combustion core or specifically in the Heat
Riser, and any pipe that we use for the Horizontal chimney within the Thermal mass should be considered to be a sacrificial form, to be made with the
cheapest piping possible around which our more permanent cob and cob/rock structure will be formed!

I just took a small break, and am now doing the math. The area of ether end of your hoop house can be found to be 1/2 of a 26' circle, :::-->

Area of a circle = pi`Xs R2 the diameter is 26' so the radius is 13' , and squared is 169 square feet 1/2 of the circle is 85-ish square feet Xs 96'
85 Xs 96 = 8,160 cubic feet, minimum insulation

If we subtract your initial 12 feet plus two walls to seal off the Full aquaponic tanks and an air lock taking in total 16' 12'Xs 1/2 of a 26' circle or
12'Xs 85 sq ft = 1,020 cubic feet! Iif this is pretty well set, then this space should be heated with a Regular 6'' RMH System!

This leaves a space 80' Xs 26' available for use to extend Your Growing season by 3-4 weeks , however you plan on having a further 30 feet of
2 rows of 30 ' long 3' wide tanks holding your primary tanks with floating beds so we can alot room for insulation for both walls at floor level

outside wall membrane
==============
inside wall membrane
=============
hay insulation with vapor
barriers 24'' thick and over 30feet long
------------------

walkway 36''-ish

-----------------

1st (raised) grow tank space 36''-ish

----------------

walkway 36''wide 30 feet long

----------------
your Rocket Mass Heater
4' wide raised bed, thermal
radiator additional storage
area on top no walking
----------------

Walkway 36''wide 30 feet long !

-----------------------

2nd (Raised) Grow tank 36''-ish

----------------

walkway 36''-ish

----------------
hay insulation with vapor
barriers 24''-ish and over 30 feet long
==========
inside membrane
==========
outside membrane

Total inside width 26' please remeasure to determine actual width and plan on the thickness of the walls of your box !

Yes I think you should wall this end off and plan for a separate RMH to feet this space !plan on a second heater for this area

This is as far as I have got, the fish need the highest temps with protection from cold 24/7/365.25

The grow beds will extend the season, 3-4 weeks each end

the southern end will be for traditional crops at least for next year? Hope I have this right so far this appears to be do-able,but tricky like this ! Big AL

Late note : You asked for a do this list, L@@K at the last suggestion In the last line that I Gave Michael R. it was Golden advice and worth sharing
with you too ! A.L.

Hey, (Big) Al: Thanks for being the unofficial go-between for me and e & e.

In answer to your questions: 1) the garage floor is concrete. 2) The common wall (garage-to-house) is block on the garage side. 3) The garage ceiling is 4 or 5 inches lower than the adjacent kitchen ceiling.

I've re-posted my garage/greenhouse layout with labels to show where each of the 3 doors lead to from the garage. Perhaps this will make more sense as to why I positioned the RMH where I did. Putting it on the east wall would prevent easy egress in and out of the garage.

I visited the VillageVideo site and got to the youtube videos. Thanks. I was not aware of that resource.

In any case, while I appreciate the details you provide, however, I still need an answer to my question (which is): based on what I want to do, which of e & e's RMH plans should I buy?

I should also add that Erica did respond to my question several weeks ago by saying (and I quote) "From the floor plan you sent, it does look like the greenhouse heater plans would be the best choice. The plans include several layouts, and the basic down-and-back layout can be shortened to fit your space (or you could extend the bench toward the corner if you prefer).

The problem is, I couldn't figure out which plan she is referring to. I did not see any plan called the "greenhouse heater" plans.

Is "greenhouse heater" code for something only permie insiders know?

Michael R. : O. K., I'm slightly more confused myself -taken from beginning to end !I was guilty of assuming that the Northern door went outside , Without that door
for wood feed ing duties I would turn the RMH around to have the Feed tube close to the door that the wood is coming in! I cannot see why the common wall is not
the best location. Your entire RMH is going to be about 15' long and 30''-ish wide, in that location it can help heat your house ! With your location we must protect
that wall and the floor from becoming a heat sink and heating the outdoors , that would be my least favored location! My second choice would be the center of the
room !

I just rechecked ernieanderica.info/shop and I did not find anything any different from what you apparently did ! There is no coded message or secret hand
shake

Again, Martha my wife and I feel very close to Ernie and Erica in spite of only brief contact via e-mail the last two years. They both care deeply about their craft and
I expect that they will be returning to full capacity shortly! I would make sure that they are aware that you are making a new inquiry and that there was confusion
in the last round of e-mails. As much as I would want to suggest a set of plans, I will leave that to E & E as I am positive that they will see you done right !

In the mean time go to the web address I highlighted and scroll down to the part that says parts and accessories while this is very helpful -in the last paragraph just
above there appears the highlighted word phrase site planning page click on that these two sections are worth there weight in gold ! I hope this helps and is
timely ! For the Good of the Craft ! Big AL

Michael, what are you using to do your drawing? I need something like that!

Hi, Marci: I'm using the Adobe Creative Suite, which is very corporate and un-permie-like, I know. But I taught it for years and still have access to it even though I've retired from teaching.

I have tried to move towards [free] google products despite some philosophical apprehensions I have with them lately. Google does have a Drawing app that, while simple, would probably work if I had to go that route in the future. Check it out.

Now I've got to look at what Big Al is telling me and see what I can do with his response.

Ok, I'm back, Big Al: First, thanks for reminding me about the Parts and Accessories portion of the e & e website. I had been there some weeks ago, but with all the different online resources, it's hard to keep track of where I saw what. I had not seen the Site Planning page, and that is pretty deep; a child adoption questionnaire, I imagine, is probably as detailed.

As far as RMH location, remember, my goal is first to warm soil that will sit above the bench and then to keep just the (by that time) greenhouse warm. The house is not a consideration. I do recognize that having the RMH on the west wall means it might be a good idea to insulate the wall and the floor, too. The other advantage I'm hoping to leverage is the window on the west wall, which I had hoped I could run the exhaust pipe out of. Going through the ceiling would be a real ordeal since the roof is flat and is covered with a rubberized leak-stopping material which I'd rather not disrupt if at all possible.

Your point about e & e "doing me right" is well taken. They seem like good people. When you say "I would make sure that they are aware that you are making a new inquiry and that there was confusion in the last round of e-mails", I kind've did that via multiple e-mails, calling twice and leaving messages for them to call me . . .

I don't know what else to do unless someone out there who has top secret contact with e & e can put in a good word for me. I think I'll stop typing for now. Thanks to all who care to be of assistance, you, especially, Big Al !

Michael R. O. K., I'm weakening, but we have to both supply you with a large thermal mass / Heated bench and ensure that you have a strong draft to carry
the the exhaust out through your final vertical chimney! It is very likely that your final vertical chimney will be Taller and more prominent (noticeable) if it
has to create a strong draft with two 90 degree elbows in its middle( as in turns to pass through the window, and then turns up again )!

Please send me a picture of the window and detail its size and distance from the ceiling ! F.T.G.O.T.C. Big AL

Ok, I've tried to incorporate the suggestions you've made, Al. Michael, you inspired me - but all I have is Publisher so the detail is nowhere near as good. But here's a bit of visual.

Michael R. : The Truth is- I had lost the location of these gems of information pretty vital to a successful build ! YOU provoked me to re-locate them

Especially valuable to you and to anyone doing ether a 1st Build or a build after a long break is the site planing page highlighted in the paragraph
just above the start of the Parts and Accessories Section, together they help you prepare for the build, and make sure that All your materials are on site
when you are ready to advance step by step through your Build ! This can be important when you end up with people standing around while you run to
Lowes or Menards for your 3rd trip of the day ! F.T.G.O.T.C.! Big AL

Marci : I am sure that you will re-skin your Hoop House carefully, and the resulting structure will be tight ! This brings up some housekeeping issues
to cover now ! I am sure that your sun has a better handle on air exchanges and humidity issues than I have. You will have water running off of the
inner membrane, and onto your Hay bail insulation, Without an early effort to seal off your hay from water saturating it you will go from insulation to
to a row of blocks of ice on the inside of your Hoop House and frozen to the floor of the hoop House !

Here just a little care with recycling your old Poly cover to seal and protect the hay bails should pay you big dividends !

The Top surface of your Rocket Mass Heater (s) RMHs is porous, mostly we expect that the stream of water vapor will be form the RMHs interior to
its outside. The Flat Top which can be sloped for drainage can be as large/massive as you want, having the top of the RMH available for use as a Seed-
starting warming bed should be part of your plan and its height should be adjusted you the comfort range of the Workers backs ! Sheets of poly here
will help protect its top ! O.K., lets move on !

Marci :
The fish tank room : Here I think you have allowed yourself room for expansion, fine, lets go for it as is, I want to caution you that you will need to

Mark out an area on on the floor this goes here, that goes there, and make sure that you really can walk around your Aqua-ponic tanks And work on
them! Finding out you need an other 6'' is just as big a deal as needing 2 feet, Tearing down walls and/or finding that your cement floor is too small
for for new locations of your aqua-ponic tanks can be avoided by planing now !

I am assuming that your Second room with tanks and floating grow beds is/are designed to be roomy enough for expansion ! Is there a chance that
you could combine the two rooms to conserve heat with plans for future expansion ! While I understand my #1 Job is to give you a rocket build with
enough heat to protect and allow growth of your fish families , I still have no idea by how much you have extended your Growing Season. I hope
your plans are conservative enough to allow us the ability to provide a cushion that might be increased/shrunk as weather and demand require !

There is also the issue of uncoupling the concrete slab from the outside walls with some insulation, otherwise we will be trying to heat the Ground,
and from there the air outside Your Hoop House !

Marci :
The DWC floating beds room ! Again With or Without a start date for your growing season I am planning on hay bales running along both East and West walls.

So we narrow your room by 2 feet, both walls! Then for walk-around room at your DWC beds we need 3 feet out from the wall to the 1st tank, 3' for the tank,
? for the gap between tanks, 3' more for the 2nd tank and then your main work area ! Again, you want to lay it out to see what you actually need for room !

Oct 9th. you were looking at (3) tanks 20 foot long, so now you are talking 2 rows of (3) tanks 20' long. With walk around room, say 70' then two walls, - -

How does that check out with you ? We are probably talking about 2 dedicated RMHs with two dedicated final vertical chimneys, it might be possible to combine
the two rooms for the 1st year ! And expand forward next year ! We Do have options ! I need your input ! 4 the craft! Big AL

Hi Al, thanks for your comments. I'm thinking I can clear a few things up. First, the two rooms are not separated by any wall. The concrete pad is going to be installed simply to keep the fish tanks level. The drawing isn't to scale, but my hand drawn one is (with lots of erasure marks, too). The second row of DWC tanks isn't definite yet - just trying to see what can fit. The remaining floor i think will be stone of some sort - hoping to have something that will also retain some heat. And yes, it will be sealed up good and tight. Good idea about covering the straw bales with the old poly, we had already planned that they will be used as mulch bales next year.
Now, as for the growing season - we currently have extended seasons (thanks to the high tunnel.), and will begin offering a winter CSA share in conjunction with our regular season by the end of next year. The primary produce for that will be grown in our other tunnels/greenhouses using some of Elliot Coleman's methods. Our goal for the aquaponics is to grow all year - with the produce grown dependent on the season. I'm not expecting to grow tomatoes in December - but Kale and Lettuce should be able to handle lower temps. My fish need a fairly consistent temperature of 68 - 73 degrees, which I am maintaining now with tank heaters. That heated water is then pumped throughout the system every 15 minutes.
So, with that in mind, do you think two RMHs? Should they be head to head, with exhaust out to each end of the tunnel? Or further apart? And when you mention the moisture, I was concerned about cob being used in a place that - by its very definition - is wet, wet, wet. Will the heat keep it dry? You've been so patient and I appreciate it. I feel like I have SO much to learn.

Marci: You're way too modest. Your drawing is excellent !

Marci :I am concerned that you have not yet acknowledged my remarks about needing more insulation, The Fish tank room needs to be isolated
from the rest of your hoop House, I need at least the dates that you are NoT going to be using your DWgs floating beds for food production we
need to figure degree days and fuel usage You are still growing tomattows, what is your planned shutdown date, and when do you NEED To Start
food production !

To be blunt you are asking me for recommendations that will affect your livelihood without giving me enough information to have an informed
opinion ! If I was your next door neighbor I might be able to guestimate an answer, which might cost you thousands, not a responsibility I want to
take on !

Please ! Go to Rocketstoves.com Now and purchase the Download PDF version of Rocket Mass Heaters. I need to be able to have you
refer to a hard copy as we proceed further! within 5 weeks I will be offline somewhere in the Southern states ! Big AL

Al, sorry - i certainly didn't mean for you to feel like you would be held responsible for my choices. I've given you all the information I have - there is no "start" date as we are already in production. There is no time that the DWCs will NOT be in service - but they aren't even built yet. The tomatoes will come out this week, and we will strip the poly and begin on the floors. I have considered the insulation - and every other recommendation you've made - carefully, and am trying to incorporate it into my plans. I already have - and have read several times - Ianto Evans book on Rocket Mass Heaters. That's why I had compiled my materials, as I stated before. I have also completed E&Es site planning page - very helpful!. I just still had some questions. Our objective is to be in and operational (tho maybe not productive) by mid November. Otherwise, I will be eating little tiny fish sandwiches with little tiny lettuce leaves for the next few months.

When I look at the rocket stoves for green houses I kind of wonder if we should not be designing in water heating coils in our mass heater designs.
I know some have them some use air to transfer heat. But I am thinking that fluid transfer will offer a number of advantages if it is included.

1) One can add solar hot water collection to such a system. It just is a matter of waiting to high enough liquid temperature before trying to transfer heat.
2) Fluid transfer can utilize paraffin thermal energy storage devices that can allow for modular design and take up less space. Such units can be used even in wet conditions since they are self contained.
3) Fluid bed would allow for creation of bio-heat capture from composting materials in a unit next to green house.
4) Fluid bed can be heated by production of bio-gas digester in a gas burning unit that is not part of the rocket stove. It would be able to tap into existing infrastructure.

It would seem that it would take little effort to include the capacity for fluid heat transfer in the design of a Rocket stove for a green house. It should have little impact on the functioning of the radiant heat or air flow systems when not being used.

I am kind of leaning more towards the thermal banking greenhouse direction with the Rocket stove being the backup heat source that is in the link below.
One thing I liked about the thermal banking greenhouse design was that it included a drying room as part of the design.
It also is as much of a cooling unit as a heating unit. If we are going to spend the money on thermal banking we really need to make sure it can be used for both heating and for cooling in the greenhouse.

http://cookingupastory.com/sustainable-energy-thermal-banking-greenhouse-design

Design plan can be found in PDF at

http://www.sare.org/index.php/content/download/50802/668040/file/Schwen%20Greenhouse%20Diagrams.pdf

Alex ;Thanks for finding and sharing, this duplicates some of the work done by Fellow Member Rob T. (Bigelow Brook Farm on U-tube )

Even though there is no attempts at present to add in ground piping to The Wafati systems here at Permies the most basic idea , using
the summers heat load to 'charge' the thermal mass under the Umbrella is being tested now ! Big AL !

Marci : I still have no idea about your willingness to add some insulation to both the east and west walls, Because failure is not an option we must protect your fish !

Just like a nearly empty refrigerator loses more Coolth when you open the door than an identical Well stuffed refrigerator, because the nearly empty one is full of
cold air that falls out onto the floor when you open the door ! You are creating the same problem with an under-loading of your Fish rooms capacity/volume !

Additional 55 gallon drums filled with water and stored within this room will help tremendously!

I am still guessing that the true finished size of your Fish tanks are- when installed, exact or smaller, you have not specified an amount of walk-around room !
and i have zero idea of your fugue plans for expanding are ! while ! am convinced that one 8'' RMH system can heat the combined areas to the temperate required
for the temperatures needed by your lettuce and kale this is two big an area to heat to happy fish temps. a wall between these areas- perhaps with sliding doors will
solve much of the problems.

this is where i wander off in my head to sketch a lay-out Big AL

Al - Yes! Yes! Yes! I'm willing! Have been up measuring, staring, walking around - trying to determine the best way to go about it. Foam board between concrete pad and side walls? Full wall on sides in fish area? I like the water barrel idea, too. My tanks are 44 inches wide in the frames, but i do want to plan for a larger tank eventually - either home made or purchased. And the area looks empty right now, but add in biofilters, the grub bin and shelving, air pumps, etc. ... and still have room to work around my tanks. If I do a side wall in that area, i'll lose about 3 foot of space on each side because I'll have to attach to the first purlin. We're already in agreement with you on the wall between the fish and the grow beds / DWCs - making the fish area a separate room, essentially. The only reason we were thinking we needed to keep it open was for heat radiation. But if we close it off, and then have side walls, our area is then 12 x 20. Is that too small for a RMH?

Marci : O.K., Next is to Google up a site that lets you find the average number of degree days of heating for your zip code and have it Book marked!

Then get a handle on the idea of how to measure Degree days!

I expect that shortly we will crack a safe way to heat water directly, warming the fish water, and then by degrees the fish room, That day someone else
will be your facilitator! and we will have batch boxes that can be loaded and left unmonitored for much longer periods and getting more or less BTUs will
be as simples how much wood you load into the rocket !

Here I want to talk to you about suspending mylar sheets above the fish tanks and RMH There is a aluminized material that comes looking like big sheets
of Shinny bubble-wrap, this waterfall reflects back 85% of all radiant heat energy and if you can visualize it hanging over the fish tank and RMH, you will
have a handle on its night time and cloudy day use if should work to save you a lot of Wood BTUs

O.K., Layout from the north end inwards approximately 4 feet of dead air space/wood storage two sets of doors for loading stacking and usage, otherwise
next spring/summers wood will be stacked in front of last years driest wood ! This is an excellent place to put down some poly as a vapor barrier and then
crusher run stones to create a firm floor area that will not retard drying. If pallets are used as dunnage to hold wood up off of the floor plans for keeping
this a safe walk are must be made and weekly checks made to inspect!

Fish tanks along east wall, doors into this area should be on the west side, away from fish tanks, 55 gal drums as 1/2 walls to temper cold air falling in !

I visualize sliding type doors with oversized handles to use for opening with a bump from a shoulder /elbow /or Hip and counter weighted to close
automagically ! like the way you see fire doors in factories rigged

if your fish tanks are 44'' by 44'' and not 3' by 12' then your profile is different! How much room between the insulated wall (at the Purlin ) and the tanks
must you have for yearly cleaning?

Parallel to your 1st row of fish tanks we will set up your 8'' rocket system leaving room for a partial second row of fish tanks too best use the lay out this
should still give you rom to walk between tanks and still have some space along the cooler west wall !

My present plan is for You to build an 8'' Rocket Mass Heater within inches of the center of the Room favoring the east wall and the existing fish tanks,
with the burner base near the north wall and the horizontal run of piping running due south to within 2' of the south awl use an elbow and a clean out 't'
turn 180 Degrees back to just past the burner base and then 8 feet paralleling the north wall then a final clean out and climb up 7 feet before leaving out
through the end wall at an angle 45 degrees to 60 degrees off of the horizontal to the outside where the pipe will rise vertically to appoint 4' over the top
of the hoop house !

Keep plugging if I have misinterpreted dimensions any where now is the time to re-draw not later ! Big AL

allen lumley wrote:Alex ;Thanks for finding and sharing, this duplicates some of the work done by Fellow Member Rob T. (Bigelow Brook Farm on U-tube )

Even though there is no attempts at present to add in ground piping to The Wafati systems here at Permies the most basic idea , using
the summers heat load to 'charge' the thermal mass under the Umbrella is being tested now ! Big AL !

Would it also pay to develope a pocket of ground cooling. I have seen amonia filled piling used to keep ground frozen. If you have an area you need cooled in some areas it would be cool enough for amonia to condense and drop down a pipe as liquid. The liquid would transfer heat becoming a gas. If conditions are right you can freeze soil or water. For that matter you can just freeze barrels of water store them in insolated area.

Hey guys, I had a post in the main forum, but I see all greenhouse queries are getting directed here.

My situation is that I need a small, temporary rocket stove for my 14 x 14 greenhouse. Also, it HAS to be inside. I live in Victoria, BC, so I really only need the stove operational for Nov-Feb, so the ability to disassemble it is a must. I was thinking of making the whole thing out of bricks and I see a few designs like that for "campfire" RS's, but would that be suitable as a "mass heater"?

Here is what my greenhouse looks like from the outside. The turbine heat vent on the right side will double as a smoke vent in the winter for the rocket stove.

Jeff Favelle : May I have a shot at modifying your goals a little? There is a very common mind trap that everyone with a limited amount of
space falls into!

About the 1st permanent improvement you make in your green house will be to figure out how to get things up off of the floor and save your
back! Here is where the Rocket Mass Heater RMH, shines, You will have ready-made benches, and heated seedling beds for ever! As soon as
you are inside your Greenhouse you have palace to set things down !

I even expect that as you start out at the very beginning of your growing season you will wish for a 1/2 dozen 55 gal drums full of water to
temper the temperature swings in your greenhouse every time you open a door! The amount of crowding you find acceptable will change
according to your needs !

Speaking of setting things down, Now is the time to think about An air lock type of shed addition to reduce cold air falling into your G'house
in the early days/weeks of your growing season every time you need to enter or exit your Greenhouse!

Because your RMH demands small, very dry, fine split wood, storing your wood within the greenhouse with its high vapor content will be a
problem! You can create an attached air tight wood box to load from outside, and unload on the inside, with the ends of your building being
preferred, Not under your eaves with their snow load !

You certainly should have enough ventilation, I am quibbling over your word choice Smoke Vent This would imply to many that you
were not planning on connecting the two together with hard pipe, This may or may not work for you -most of the days of your growing/heating
season! When your rocket is fired-up and running you may not have a problem, except with cold starts !

My recommendation is to try it your way, but to have a budget that allows for needing a Tall Vertical Chimney at least 4' over the top of the
greenhouse roof, and any nearby object bigger than a TV Antenna ! For the Good of The Craft ! Big AL

Hey, Big Al: I have not been ignoring your last comment to me, including the request for photos. I've been tied up and am currently sitting in an urgent care waiting room. I shot the photos on Sunday and once I get things under control I will upload them to permies. By the way, I did get a response from Erica over the weekend:

The best resource for the recent workshop build would be our new book, the Rocket Mass Heater Builder's Guide.
I'm working through the edits and hoping to bring a draft of it out online this week.

Yours,
Erica W

I'm encouraged, but, once again, this doesn't tell me which plans to buy. I'm confounded that it's so difficult to get an answer.

Thanks for the reply Allen!

Heated benches are out for me, all I want is ambient. All my seedlings are grown in a tropical room inside so heated benches is not on my list. Great idea though.

I should have a decent amount of thermal mass as I will have raised beds and the concrete slab I poured is 6 inches thick.

As for stuff on the floor, the only thing on the floor is the raised beds and even then, the working height for them is 24 inches high at the soil level (so likely 4-feet high at the plant-harvesting level).

As for temperature swings, living in Victoria its VERY mild. I mean very. Christmas is usually a plus 8 degrees Celsius and the "heat" of summer hovers around 22C.

Wood supply is infinite as I have two woodworkers in the family. Any size and any type of wood is at my disposal.

The turbine vents are 14" diameter. In the summer they will be wide open. In the winter, the left one will be closed up and the right one will have a 15 x 15" piece of wood attached to the bottom to seal it. I'll cut out an 8" hole in the center to affix my vent pipe.

So I just need a design. That's the part that is getting me confused.

allen lumley wrote:Jeff Favelle : May I have a shot at modifying your goals a little? There is a very common mind trap that everyone with a limited amount of
space falls into!

About the 1st permanent improvement you make in your green house will be to figure out how to get things up off of the floor and save your
back! Here is where the Rocket Mass Heater RMH, shines, You will have ready-made benches, and heated seedling beds for ever! As soon as
you are inside your Greenhouse you have palace to set things down !

I even expect that as you start out at the very beginning of your growing season you will wish for a 1/2 dozen 55 gal drums full of water to
temper the temperature swings in your greenhouse every time you open a door! The amount of crowding you find acceptable will change
according to your needs !

Speaking of setting things down, Now is the time to think about An air lock type of shed addition to reduce cold air falling into your G'house
in the early days/weeks of your growing season every time you need to enter or exit your Greenhouse!

Because your RMH demands small, very dry, fine split wood, storing your wood within the greenhouse with its high vapor content will be a
problem! You can create an attached air tight wood box to load from outside, and unload on the inside, with the ends of your building being
preferred, Not under your eaves with their snow load !

You certainly should have enough ventilation, I am quibbling over your word choice Smoke Vent This would imply to many that you
were not planning on connecting the two together with hard pipe, This may or may not work for you -most of the days of your growing/heating
season! When your rocket is fired-up and running you may not have a problem, except with cold starts !

My recommendation is to try it your way, but to have a budget that allows for needing a Tall Vertical Chimney at least 4' over the top of the
greenhouse roof, and any nearby object bigger than a TV Antenna ! For the Good of The Craft ! Big AL