New build not getting hot enough-Help...

Hi, This is my first build and I have it running well but not hot enough. It is in the greenhouse and I am reluctant to cover the ducts with mass until I know I can generate enough heat. I am afraid that my heat riser is too far from the top of the barrel or that I shouldn't have listened to my partner when he had suggested that I should use 6 inch duct instead of 8in duct when I was the one who read the book and should have known better. So... this thing is at my work and it has to work because it is 26 degrees at night for the next week or so and I really want to save the tender perennials so I don't have to buy them again next year which is why I sunk a chunk of my budget into building this thing well. Please...any suggestions?

Hi Maura: We need more information! Details of feed tube , burn tunnel, heat riser , how far is your riser from the top of the barrel ? How much steam is coming out your chimney ? How much wet cobb do you have ?How big is your greenhouse ? send pictures! The only reason to not start covering your ducts is if you might decide to switch to an 8" system, otherwise start to cover them. Cobb takes time to dry and your heat output is greatly reduced until it drys out! It will work when you have it rite! It's 0-7 here at night and my 8" system keeps my 12x20' detached greenhouse around 40 degrees ,and thats letting fire go out around 10 pm and not relighting till 7-10 am! I should add that at these temps, the fire is going all day to keep the inside temps that warm overnight.

Maura Lynn : Welcome to Permies.com, our sister site richsoil.com, and a Big welcome to the Rocket and Wood Stove Forum Threads ! Lets get you started, but
don't forget to check out a few other Forums after you get your Rocket/Dragon Sorted !

Location, Location, Location ! Look at your name and then l@@k at mine, we are asking everyone to go to the Permies Toolbox at the top of this page, Find/clickon> 'MY PROFILE'
and add your general location and your Climate zone # if you know it ! It will help us help you diagnose problems, and you might have a near neighbor with RMH experience !

Also how big is your green house ? If you can keep the air a few inches above the ground above freezing and then add row covers, then your soil can play its part to keep tender
plants protected from frost !

Were you able to do a test burn before you moved every thing inside? or were you being pushed by the weather undercover ! Basically, are you getting that nice Rocket Roar ?

Are you able to light your rocket and keep it running? Dry wood is very important at this point, I have lived in houses you Could throw a cat Through and had to bake the next load
of wood in the oven to keep a fire going with what was available ! Bake and Burn, Bake and Burn !

The last 1/3rd-ish of your horizontal chimney/ductwork should slope towards the final vertical chimney and ether a clean out or an ash pit inline should be lower than the manifold
where your hot exhaust gases turn from falling vertically to flow into your horizontal duct work !

Yes it is possible that your gap needs changing but you need to tell us a little more about what it is and is not doing to allow us to help ! In the meanwhile, I know that it seems
you are going through a lot of wood and you are, this will slow down as your cob dries out ! Big AL !

Oh thank you for the prompt reply...I have had a heck of a time figuring out how to post the pics so it took a while...had to find someone less techno-phobic than I - which wasn't that hard:) I'm on Orcas Island just down the road from the Bullock place ( figure you might know where that is) Zone 8b I think and have moved here from coastal CT. - big difference and I'm having so much fun! The greenhouse is 15' (ish) by 30' (ish) and leaks like a sieve. I've bunged up all the holes I could find and have two space heaters running and heat mats on.
My cob is still wet and I haven't committed to covering the barrel yet either because I'm not sure if I have to change anything. My heat riser (not shown forgot to take pic) is just under 3" from the barrel top I plan to bury the ducts for now as I realize that I need a clean out duct in the bed and will have to do that before I commit to that either (hmmm. fear of commitment!). The sizes of everything else is taken from the book and the Bonnybrooke build plans that I bought online. I insulated the heat riser after I sculpted the air channel (shown) and smoothed it out and insulated down to the ash pit floor from the riser. It is insulated with the slip and vermiculite combo inside hardware cloth packed around the heat riser. The clay/sand cap is rounded and slopes BOTH directions...oops. I get a clean burn and it smokes very little (just when I light it for a second)- now that I have added an extra slit brick into the feed and lay a brick halfway over and at an angle. I"d rather avoid having to buy new duct if I can. I'm in pretty deep as it is.
The pics are on a co workers flicker account as we couldn't figure out how to get them on here.


Thanks so much!


http://www.flickr.com/photos/thianzmom/11227681523/
http://www.flickr.com/photos/thianzmom/11227586816/
http://www.flickr.com/photos/thianzmom/11227651083/
http://www.flickr.com/photos/thianzmom/11227551196/

Maura Lynn : W.O.W., 8 Elbows, and it works ! we usually figure (1) 90* elbow as putting as much drag on the system as % additional feet of straight pipe So-an additional 40'!
I just counted again and you must have (1)more where your horizontal goes to a vertical chimney, - a 'T' with a clean out cap ?

I do like that you are running your horizontal pipe back by your Rockets Burner, this is a good way to guarantee a little heat is available to help maintain a draft on really cold
days ! Probably not all that common occurrence !

You definately would be more rockery with several less elbows, but you want to grab all the heat that you can, again how does it sound and how high is your chimney?! BIG AL !

Thank you for the reply. The elbows were to try to figure out how to get it under the floor and into the center. That's a lot of drag isn't it? It doesn't purr but did when I built it outside before I added the barrel and all the pipes etc. Along that wall is a battery of water filled barrels sunk into the floor quite a bit - I was loathe to move and re-bury them. If I bite the bullet and dig them up I can take most of the 90's out. I'll let you know how it turns out. Thanks so much - this was driving me nuts.

Maura Lynn : Dozens and dozens of people can start and finish a successful Rocket Mass Heater RMH build following 'The Book' and never have an issue that the answer isn't there,
then someone like you comes along, trying to make modifications to their existing set up to fit in an RMH, and It is the specific issues of the site that works or doesn't every time!

There is a rule that everyone should follow-and it isn't In the Book now. ''When the barrel goes on, the vertical chimney should go up !'' This immediately tells you if you have a
problem with the guts of the Rocket burner, No trouble, lay out your horizontal stove pipe and attach your vertical chimney,clearing any near-by obstacles by 5'-6' and see if it does
sound and acts the same ! If it works, move it indoors! If it doesn't its then time to simplify your life!

If every one had 'The book', made a decent manifold for the transition zone and tested their build with and then with again this really would be a simple project that could be started
by the 1st of October and finished before Halloween ! Every days like a wedding ! Big AL !

hey maura, I would cover the pipes with fill, or cob now, and keep a continuous burn going while your doing it. (saves time) Since your already invested, and it looks like you have a nice working model...go for it, burn that thing the way it is, till it drives off all of the moisture in the dirt & mortar. You can't hurt it, crank it up.

DRY WOOD, the drier the better, dry fuel wood absolutely burns easier & hotter. Use bricks to regulate the air intake, temporarily use a hair dryer to add more air if necessary but mainly...burn that thing hard as you can. Once the wet dirt & cob gets burned completely dry, then you will be satisfied. Eventually you want all the cob covering the pipes also dry. Could you verify that you have a vertical chimney, or are you letting your heater exhaust horizontally near ground level?

Posting pixs is easy, if the pixs are already on your computer, and if you have already resized them to a small kb size (30-200 kbs is a good size to post to the internet). Then when your posting a post...find the 'Attachments' tab next to the 'Options' tab, from the 'Attachments' tab, it shows: "Filename" and a "Browse..." button, click that. A pop-up window will occur, select your pix that you want to upload...click the "Open" button. The attached pix will not upload until you hit the "Submit" button, give the thing time to upload the pix. The pix should show up in the post along with your text you provided in the text box.

james beam