I am brand new to posting here. Hope I do it correctly. I am in planning stage to build a RMH in a 1000 Sq ft., concrete building in High Desert, 4000 feet. I currently heat and cook on a
Monarch wood stove. The small fire box has to be stoked, as you all know, on a pretty regular
45 minutes basis burning oak squares of 2 x 6.
I assume the same schedule will apply to the 6 inch RMH. Is that correct? Some real life experience with the time parameters for filling the stove would be appreciated.
An RMH batch heater 6" will burn through the wood at about the same rate, 45 minutes. However, these batch stoves are designed for slow release heat so you may not need to reload as often. Peter van den Berg suggest building a larger stove as it is difficult to overheat a house with a masonry style stove.
If you meant tending a j-tube style RMH, you are looking more at every 15-20 minutes. I have an 8" j-style and i feed pine wood every 10 minutes or so.
Here is the link to the batch rocket designs and much much more information.
Thanks for the reply and information-rich site you provided. Unfortunately the site contributes to my
"analysis paralysis." I been trying to evaluate this type of system for years. Limited abilities/funds
to build one, creates my return to KISS "keep it simple stupid." I presume that is what Wisner's plan is.
Is that so, in your opinion?
I believe I should build a 6" Wisner's original plan from Portland. Having looked at innumerable ideas.
I return to the Wisner plan. I have the Permies free plans of Wisners. I am willing to pay those folks or
others for simple plans to build. I believe in paying that poor guy Ernie, who can't get a word edgewise,
with Erica lecturing.
My building is 1400 sq ft, solid concrete floors/walls at 4000 ft elevation, so it assumes outside temps in winter.
Wisner's 6" stove and my Monarch will hopefully keep the insulated 800 sq ft portion warm enough. Someone
with wool clothes on, will be happy to sit and stoke the fire. Does that sound reasonable in your experience?
Thanks in advance for your time.
If you are good with sitting in the room to tend the fire and the batch box adds extra complexity then a J tube will work well. I see a couple different space numbers there, 1000sq ft, then 1400sq ft and 800sq ft insulated. Will the RMH be located in the 800sq ft space, or one of the other spaces? The RMH delivers a lot of radiant heat and conductive heat, so the best results are being on/near the RMH.
The original J tube design can be made for very low cost using recycled/used parts and cob. You can (and should) lay everything out outside to make sure you have all the bricks you need and even test fire outside, and when happy with sizing you can move it all inside piece by piece and use clay slip to mortar the bricks together.
Are you planning to replace the existing stove, and recycle the chimney opening? Cooking on the barrel of the RMH is possible but a bypass might be needed if cooking without a desire for heating. Combining chimneys to 1 point is not advisable.
I'm not quite a lumberjack, but that's OK, I sleep all night and I dream all day; I'll coppice trees, I'll grow my food, and compost poo and pee! With a well and off-grid solar, it's a permies life for me! https://www.youtube.com/watch?v=FshU58nI0Ts
Hi Gary; I have lived with my RMH 8" J tube for 5 years now. Its out in our green house/ studio. We keep it warm all winter with our RMH. So a trip outdoors to stoke it.
After it is up and running, I add wood every 45-50 minutes, that's it. I set a timer . If I mess up and let an hour + go by ... sometimes the last piece of wood will still be there ready to burst back into flame... If it's completely out, it will be so hot in the bottom of the feed tube that some times new wood will spontaneously burst into flame... if not paper and a match will do it.
Myself, I could build a batch box (they do burn hotter) BUT ...they only for last 1 hour... for the extra 10-15 minutes I'll just stick with an 8" J tube, much simpler to build.
I suggest that you do the same with your 1st build.
Cost wise a J tube of 6" or 8 " can be built for under $200.00 less if your a scrounger. I maybe spent $300.00 on mine buying brand new stuff. Labor wise, moving materials / mixing cob / stacking brick . It's nice to have help.But I didn't . Takes more time but one person can do this. Somebody else in your area could be interested enough to help build yours in exchange for helping build theirs. Technical wise, if you can read a tape measure and follow a simple plan it will be easy. RMH's seem daunting when you are reading about them, but after your building it you will realize what a simple design it really is. I mean, Boy scouts build them... Be extra careful on your measurements at the core and at the horizontal transition area and the rest is just burying a pipe in mud with lots of rocks.
If you don't have it yet, buy the Wisners Builders Guide. Maybe if your a visual person then buy the CD's. Cruise the RMH forum here and at Donkeys. There is an amazing amount of free info here for the reading. As you progress take pictures and post , ask questions here, we like to share info.
I call myself a Rocket Scientist.... but its really not rocket science.
Gary; The difference between your Monarch and a RMH is how long you have to burn to stay warm.
Your cook stove needs to be constantly burning to stay warm and will cool off in 2 hrs if let go out.
A RMH will share its heat for 12-24 hrs. It can be lit for a few hours in the morning, let it go out all day , relight at night while your awake and let it share its warmth all night while your sleeping.
Never a chance of chimney fire , no creosote , no smoke ! Its a win win
J tube or batch box, no matter which you build it will burn less wood and keep your home warmer longer than your Monarch.
For a 1400sf barely insulated building, I would go with an 8" J-tube for simplicity of building. It will be hardly any more work to build, only a bit more for materials (particularly chimney/stovepipe if you need a new one), and will deliver around twice the heat in a given amount of time burning compared to a 6" J-tube. A 6" batch box is said to give about the same amount of heat per hour as an 8" J-tube, so if your tending time is seriously limited, you might want a batch box.
My 7 1/2" J-tube with seasoned hardwood burns down in 40-50 minutes, and can easily be relit just by loading smaller wood if I get back to it within an hour or so. I tend to use medium sized wood, not finely split pieces as seems to be the consensus. Once the fire is burning well, it will keep going strong when loaded with wood that only fits three or four pieces at a time. I keep a piece of cement board partly covering the feed tube while burning to limit excess airflow and concentrate the heat in the firebox. Others use bricks.
About the worst that can happen if you build an RMH that is bigger than you need is that you don't have to load it more than once or twice per day. If it has an exposed barrel, you might get overheated while the fire is burning; just open a window and get some fresh air if this happens.
Joel Salatin has signs on his property that say "Trespassers will be Impressed!" Impressive tiny ad: