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Wood stove for yurt - RMH, pocket rocket, barrel stove?  RSS feed

 
Dan Woloz
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Trying to decide how to heat a 16ft yurt over the winter with low temps of 20-30f

Was planning a RMH but concerned it won't be sufficient given the leaky and poorly insulat d nature of a yurt
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Dan Woloz : I am not interested in breaking your mind, or even bending it, I just want to point out that like the belt that holds your pants up,
the two of youhave reshaped each other just a little and a new belt just will not have that same fit -it won't 'Fit' even though its the right length.

Here goes, I promise no one is going to try and measure your inseam.

Here in North America we are in love with the Fossil Fuel Fired Forced-air Furnace, It does its job mostly because we force it to. Air is an
insulator, in a down coat it is the air trapped in the feathers, rather than the feathers that keep us warm, adding in more feathers will actually
reduce the amount of air and more feathers will actually make us colder!

So we take a near perfect insulator air and blow it past the Heat exchanger in our furnace where It accepts a small fraction of the heat at each
pass through, we have to move vast amounts of air to capture the heat energy, and then that heat transfers itself poorly to objects within the
rooms we want to heat.

Eventually all that heat energy rises through Convection and stratifies out at the ceiling, we don't live on the ceiling !

Basically we do this because forced air systems are cheaper to install than a boiler system that delivers radiant heat that sends its heat through
the air which again accepts that heat energy poorly, and instead warms the physical objects of the room, this turns every object in the room
into Thermal mass which slowly re-radiates that stored thermal energy back into the room finally starting to warm up the Air.

So All of the choices we have are capable of Producing radiant heat, can we find the one that does it better?

The barrel stove is certainly capable of producing large amounts of radiant energy, and allowed to burn hot enough will burn fairly cleanly.
It has no ability to store any great amount of heat energy,we can surround its outside heat radiating surface with a 3-sided wall of stacked
bricks or other dense material to make a thermal mass to store and slowly release that heat energy out into our room ! Some of the additional
problems a barrel heater has are when it burns hot enough to clean up all the smoke it produces, the exhaust temps at the base of the final
vertical chimney will run around 500 degrees F, so a great deal of the heat energy produced WILL go up the chimney, a lower temperature fire
is a dirty fire, which will produce creosote!

Living in a canvas sided and roofed structure the last thing you want is any heater that Could be run in a way that produces creosote and a
potential 'chimney fire'

The Pocket Rocket can not be run in a manner to make creosote, it only has one 'speed and that is full tilt [ON], though it has no thermal
mass to hold heat, a thermal mass can be created surrounding the Pocket Rocket, but here again a large portion of the heat made WILL go
up the chimney un-captured

Both of these two heaters will need insulating chimneys and special handling equipment to pass out through the wall or ceiling of a Thin
skinned Yurt safely

The rocket mass heater burns at freakishly high temperatures, burning up all volatiles, including Carbon Monoxide, a creosote fire is
impossible! As the hot exhaust gases are passed by the inner surface of the drum they dump ~ 40%~ of their heat energy as Radiant
'prompt' energy.

Again this heat energy warms objects turning everything the radiant heat hits into thermal mass storage, and only incidentally heats the air!

The other 60% of the heat contained in the hot exhaust gas travels horizontally through the Thermal mass where it gives up the bulk of its
remaining heat We try to lower the final exhaust gas temperature down to 150 degrees F or a little cooler ! No special chimney is needed, and
this is the safest heater to have in a yurt !

Generally we say that 1-2 hours worth of RMH tending while simultaneously doing other household chores will supply 12- 24 hours worth of heat
delivered directly to the body of the person warmed by direct contact (conduction) and again by radiation off of the surface of the bench.

One more example and we will wrap this up! we all have been outside, dressed for the weather, in 20-30 degree weather on a brite sunlit day
and gotten into a car that was 30-40 degrees or more warmer -simply from the sun steaming in through the cars windows, heating 1st the
interior, dash, upholstery, etc and finally the air in the car. Usually you ether get out of the car and take your coat off, or roll down a widow
because its a little too warm! Even with outside temps at 20 degrees a yurt should be nearly 10 degrees warmer inside without the RMHs fire
being recently lit. With a RMH in use a person using the RMHs Thermal Mass as a sleeping platform can be as snug as you were in that south-
west facing car in a clear spring afternoon !

A word about the size of the footprint of a RMH, to someone who is worrying about the amount of room a rocket takes up, you need to change
your view of the whole space, eventually your square mind will start thinking in circles and then you will see how nothing else could have set in
the center of your Yurt and made every inch of space within its shell barely a arms reach away ! A RMH in a Yurt is a space expander rather
than a space stealer!

I hope this helped and was timely ! Big AL

 
Dan Woloz
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Well I appreciate the colorful reply. I am a RMH convert though; definitely believe in its merits over other technologies. However, I'm unsure its suitability in our application after reading this passage from Iantos book:
"Where would I choose not to build a rocket mass heater? ... In outdoor rooms or living spaces that are not well sealed. Such as teepees, tents, etc., the air heated by a Rocket would leave the building before you got a chance to enjoy it. Better maybe to put in a stove that delivers high temperature radiation, such as a barrel stove or a Rumford fireplace."
 
Tom OHern
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Location: Seattle, WA
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Have you read through the thread on the RMH they have in a tipi at wheaton labs?

http://www.permies.com/t/29327/labs/RMH-Tipi

It sounds like it is working out well for them. I imagine it would work out even better in a yurt.
 
Miles Flansburg
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Dan, There are a few on Youtube.

Here is one with a rocket



This one may also have a thread here at permies? Here... http://www.permies.com/t/13385/wood-burning-stoves/RMH-Mongolia





There was a really nice one I saw a while back but I can't find it right now. I will have to look for it.

Here it is. It was an old thread here at permies. With a link to photos.

http://www.permies.com/t/5937/rocket-stoves/rocket-mass-floor-heater-finally

https://www.flickr.com/photos/fishermansdaughter/sets/72157625122351115/
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Dan W. There is a type of Aluminum foil that on close examination looks like bubble wrap ! It reflects 85% of All radiant heat energy
back into your structure,definitely worth investigating !

To the list you quoted, I would add infrequently occupied structures,As More the 50% of your heat is tied up in your thermal mass
this is NOT prompt heat, Putting an RMH in a structure that was not worth sealing up to the best of your abilities would be a waste
of the effort you have put into Your RMH.

Most people living in yurts now use a heavy duty raised cooking brasier, or stove to heat there yurt and even have two Yurts, a
larger summer Yurt and a smaller winter Yurt that fits inside the 1st one, just stepping inside you gain 10*F and get out of the wind,
you gain another 10*f with the second Yurt !

I have a 10' traveling yurt, and a sleeping tent that My wife and I use from January to the end of March, we will probably get all the
way to florida (where the weather suits our clothes) before starting back north !

I know of only one (mostly) in floor RMH in a yurt, such a build for a 1st time build I would strongly try and dissuade a would be
Rocketeer from even trying ! This leaves you with discharging hot exhaust gases through the side of or through the top of a yurt,
Very dangerous considering what they are made of ! OR-

Using the RMH to store that heat for after you have gone to bed ! Hope this helps and is timely ! For the Craft! Big AL
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Miles : thank you for finding this and posting this, in the 1st video the Unit that is described as a rocket stove is a Hybrid Rocket Mass Heater,
"Russian'' Masonry stove with a quick bypass that I would love to see ! The second Video was short and left questions Difficult to parse out!
again thanks for finding this, good hunting for the 3rd one !

Dan : Miles posted this as I was writing my 1st answer. Note that the Yurts Owner/Builder proclaims this to be a 2nd or 3rd Yurt/Ger and has lost
count of the number of RMHs he has built to have created this one.

I also noted his conversation about the cords and cords of wood used o heat a traditional house in Wisconsin, and how this total package works
"More Better'' for him !

Ventilation, and Insulation are important parts of every build, and critical in a yurt ! No one wants to live in a zip lock baggie, For theCrafts! BIG AL
 
Destroy anything that stands in your way. Except this tiny ad:
Ernie and Erica Wisner's Rocket Mass Heater Everything Combo
https://permies.com/t/40993/digital-market/digital-market/Ernie-Erica-Wisner-Rocket-Mass
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