Rocket stove heater - 1st project

[elyeskl]

Hi, 

I have a hollow cylinder with the following sizes: 40 cm (diameter) x 126 cm (height)
The idea is to create a rocket heater that is similar to the "Liberator rocket heater Gen2"
which I, unfortunately, do not have its dimensions.

My question is does this cylinder fit the rocket's physics ?
If yes, what is the best dimensions for the J tube (I plan to use square tube insulated from inside with refractory ceramic plates)

Thanks in advance

[dwayne]

I have the Gen 2 heater....I have also built a homemade rocket mass heater out of a 33 gal drum.

The one thing that made a huge difference in heat, is the distance of the burn chamber it to the

top of the can.   If you can keep that about 3 to 4 inches from the top, that will be your ultimate

heat output of your RMS or RMH.

One of the biggest problems I have had, in which no one tells you about, is that a RMH

hasn't really saved me anything, but has actually cost me far more than what it is worth.

Yes, the RMH burns highly efficient. 

But you are constantly fiddling with it every 15 min to feed it wood.  I have taken long

3 and 4 feet pieces of wood to allow me to go away for about a hour or so.  But you are

constantly playing around with feeding it..

The Temps of my Gen 2 run about the following:

Top Approx 500F

midway down  about 250F

Exhaust  about 125

Flu pipe around 90 to 100F

This is all measured with a InfraRed Temp gauge.

Now, with that said.  When I raised my burn chamber up to about 3 to 4 inches from the

top, my homemade RMS mimicked the G2. in temp.

The other thing that was frustrating, is as soon as the fire starts going out, you lose your

heat. The G2 weighs about 170 pounds.  Though that is a lot of mass (to some degree),

you have no coals to keep that mass hot.  Thus, you lose your heat when your fire goes

out of the burn chamber.

My 400 dollar wood stove actually uses much much less fuel to keep my house warm

than my G2 RMH.  The charcoal from the burnt wood keeps the stove hot for hours on

end.  I have a 1400 SQFT house totally off the grid at 9000 feet in the mountains.  that

wood stove weighs 250 pounds will easily heat the house and keep it warm with far FAR

less wood than any RMS out there that I know of.  Is it as efficient? NO.  But it retains

the heat far better than the RMH because of the glowing ashes inside the stove.

The one thing the G2 and G1 have over a regular wood stove, is the hopper.

The hopper allows you to burn wood pellets.  It is self feeding, no electricity, and instead

of refueling every 15 to 20 minutes, the hopper automatically feeds 40 pounds of pellets

into the fire chamber, allowing you to have a very long burn time....12+ hours without

refueling.

The Exhaust temp of the G2 and G2 is extremely low.  This means adding a Mass for

equalizing heat will take a LONG time to warm up.  This is really not possible with

feeding wood.  But with feeding wood pellets, I think you might be able to warm up

the mass enough to kind of work.

All of the above was done with a Homemade 33 gallon barrel and a G2 which was

purchased with a hopper.  The house was NOT built around the RMH.  But the RMH

was placed in the house to heat like a regular wood stove.

I have had my G2 since they first came out...approx 1 year. I had my Homemade

RMH for about 3 years.  If I were to do it over again, I would purchase a regular

wood burning stove that I have right now, and never look back.

Been there and done it.   Experimented with it, and learned the hard way.

If you want the demenstions...G2

16 inches diameter.

32 inches high.

[masonryrocketstove]

No, Dwayne. What you're describing is not a Rocket Mass Heater at all

May 23, 2023 22:16:12 GMT -8 dwayne said:

I have the Gen 2 heater....I have also built a homemade rocket mass heater out of a 33 gal drum.

from the posts you wrote before, you were using steel square tube. Of course your combustion temps won't be as high as an RMH J-tube made out of refractory ceramics. The steel burn chamber sheds heat too quickly before what is supposed to be the heat exchanger: the steel barrel. Your steel square tube combustion core is acting as a heat exchanger. ..There's one of your problems.

The other thing that was frustrating, is as soon as the fire starts going out, you lose your heat.

That's because you have no thermal storage mass after the combustion unit to store the heat you're producing. (Which would be a lot more heat to begin with if your rocket core were insulated refractory rather than steel.) If the core was constructed properly using the right materials, then you're losing the majority of your heat up the chimney. An RMH is designed to retain heat for a good 12+ hours *after* the fire goes out. That's absolutely integral to the design of any thermal storage mass heater. That's why it's called a "Rocket Mass Heater"

The G2 weighs about 170 pounds. Though that is a lot of mass (to some degree),

No, it in't. At all.

The G2 Liberator is a "Rocket Stove" combustion core and rapid heat exchanger. You're supposed to build a thermal storage mass out of masonry, cob, etc. between a RMH combustion unit and your chimney pipe. The G2 by itself is NOT a mass heater, because it has no thermal storage mass to speak of ..at 170 pounds.

An actual thermal storage mass is easily 2000 pounds or more. It must literally be "massive" to act as a thermal flywheel / emissive heat storage battery after the fire goes out. 

you have no coals to keep that mass hot.  Thus, you lose your heat when your fire goes out of the burn chamber.

My 400 dollar wood stove actually uses much much less fuel to keep my house warm than my G2 RMH. The charcoal from the burnt wood keeps the stove hot for hours on end. I have a 1400 SQFT house totally off the grid at 9000 feet in the mountains.  that wood stove weighs 250 pounds will easily heat the house and keep it warm with far FAR less wood than any RMS out there that I know of.  Is it as efficient? NO. But it retains the heat far better than the RMH because of the glowing ashes inside the stove.

The heat storage capability of an RMH's multiple-thousand-pound thermal *mass* after the fire goes out is where the biggest efficiency of a Rocket Mass Heater comes from.

Take the G2 liberator's weight.. and multiply it by twelve. That number would be a reasonable amount of thermal storage mass for a 6 inch J-tube. Most people use brick, stone, cob, or some combination thereof to build the thermal storage mass.


...Why don't you try building one to spec and operating it as intended before trash-talking the design and acting like everyone else using a mass heater is either foolish or deceptive?



What you've done is construct a steel "rocket stove" and called it a "Rocket Mass Heater" while ignoring all the critical design parameters that make a RMH functional and efficient ...then tried to operate it incorrectly, and held it to the standards of a poorly efficient instant-heat-only wood stove.

That's like building an internal combustion engine with no wheels or passenger compartment, and then claiming that cars don't work to transport people around, that your horse does it better.. and that when you fed your horse gasoline, as everyone says cars need to run, it died. 

Why would anyone be surprised in your disappointing results in such a case?

[dwayne]

Sorry,

you have absolutely NO IDEA what you are talking about

I OWN the G2 Rocket Mass Heater, and I have done many experiments with RMH and RMS.

They do weight about 170 pounds...

I know exactly what I am talking about....

Until you do some real experimentation with many different sizes and burn chambers,

do not rely on the internet for your information.

I gave you the weight and size of the G2....

So yes, i know exactly what I am talking about.

[masonryrocketstove]

Jun 10, 2023 14:45:20 GMT -8 dwayne said:

I OWN the G2 Rocket Mass Heater,

I don't doubt that you do.

They do weight about 170 pounds...

I don't doubt that they do.

I know exactly what I am talking about....

sorry... that you don't.

Until you do some real experimentation with many different sizes and burn chambers, do not rely on the internet for your information.

Until you do some real experimentation with refractory material up to the task of insulating your burn chambers... do not rely on marketing material for your information. ...Maybe try reading from resource material that isn’t written by someone trying to sell you the thing they're describing.

I gave you the weight and size of the G2....

you sure did ... swallow their marketing nonsense hook, line, and sinker

So yes, i know exactly what I am talking about.

Still no. Sorry:

Mass heaters in their current form have been around in Europe for at least the last 500 years, having been an extension of the ancient Roman Hypocaust that heated ceramic floor and wall tiles for entire room heating.

The only reason you’d think that a G2 Liberator is a "rocket mass heater" is because it is/was marketed to you deceptively as one.

And the only reason they do that is because they can ship you an inefficient steel burn chamber for a few hundred bucks… but refractory bricks and clay are heavy (...y'know.. all that *mass*...)  So they can’t UPS you a 2000-6000lb masonry mass heater. ..But they’ll gladly take your money for something that doesn’t work anywhere near as well, and market it unscrupulously under the same name as an actual "mass heater."

Sorry that you’ve been duped. You’re not the only one to fall victim to the marketing hype.

[masonryrocketstove]

If you’re doubtful about *all* information online, the two best English-language books on the topic I’ve been able to find are:

“The Rocket Mass Heater Builder's Guide: Complete Step-by-Step Construction, Maintenance and Troubleshooting”
by Erica and Ernie Wisener
(2016) New Society Publishers
ISBN: 978-0865718234
EPUB / PDF Ebook ISBN: 9781550926163 / 9781771422062


“The Book of Masonry Stoves: Rediscovering an Old Way of Warming”
by David Lyle
(1998) Chelsea Green Publishing
ISBN: 9781890132095


The first one is available in a lot of places for free download if you go looking… the second one is harder to find because it’s out of print and I don’t know of any digital copies available ..But I was able to get a used hardcopy for about $35-40. PM me if you’d like info from it. David Lyle's book is a really, really good resource, and it’s a shame it’s out of print now. ..You could probably get a free loan copy through your local library system, too.  

[martyn]

Hi Dwayne, there are some great metal box heaters available nowadays, in fact where I live you can only buy stoves that pass strict emission regulations.
Unfortunately you cant run that style of heater through any substantial mass, at least not in the same way as a Rocket stove mass heater can!
It sounds like you need a heater that will store plenty of heat, why cant you just build one based on a tried and tested model?
There are lots of examples on this forum, some use a J tube, some use other designs that burn for 1/12 hours without reloading.
We are here to help you if you can explain exactly what you would like to achieve.

[dwayne]

Jun 11, 2023 9:15:18 GMT -8 masonryrocketstove said:

Jun 10, 2023 14:45:20 GMT -8 dwayne said:

Still no. Sorry
Mass heaters in their current form have been around in Europe for at least the last 500 years, having been an extension of the ancient Roman Hypocaust that heated ceramic floor and wall tiles for entire room heating.

The only reason you’d think that a G2 Liberator is a "rocket mass heater" is because it is/was marketed to you deceptively as one.

And the only reason they do that is because they can ship you an inefficient steel burn chamber for a few hundred bucks… but refractory bricks and clay are heavy (...y'know.. all that *mass*...)  So they can’t UPS you a 2000-6000lb masonry mass heater. ..But they’ll gladly take your money for something that doesn’t work anywhere near as well, and market it unscrupulously under the same name as an actual "mass heater."

Sorry that you’ve been duped. You’re not the only one to fall victim to the marketing hype.

  I will let you go right ahead parroting internet stuff, and let you argue with a company that has a government certified

RMH, and have been selling them for years. Other than that, your information is ill informed and parroted. 

Sorry my friend...

I have spend money and time on this.... I do not go play parrot on the internet trying to buffoon people to think they

have expertise knowledge. 

I wish you a very good New Year.

[dwayne]

Jun 11, 2023 11:11:38 GMT -8 martyn said:

Hi Dwayne, there are some great metal box heaters available nowadays, in fact where I live you can only buy stoves that pass strict emission regulations.
Unfortunately you cant run that style of heater through any substantial mass, at least not in the same way as a Rocket stove mass heater can!
It sounds like you need a heater that will store plenty of heat, why cant you just build one based on a tried and tested model?
There are lots of examples on this forum, some use a J tube, some use other designs that burn for 1/12 hours without reloading.
We are here to help you if you can explain exactly what you would like to achieve.

Thank you very much.  You are the first person that hasn't tried to buffoon people.  Yes. That is a big issue in many areas.

I had to take down  my homemade RMH because of insurance reasons.  It was not "Certified". 

It is extremely difficult to build a RMH into a home.  Hard to come by with that much mass, weight.

I have spent about 1000 dollars building, testing, and getting mine to work the way I wanted. What I found out, was

lots of wrong info on the internet.  That is even with "Tried and Tested" models.  I use the J-tube. It was the easiest for

me to get going, the cheapest to experiment with while being able to exchange out parts.  I had a homemade, upside

down gasifying heater that worked extremely well, but I couldn't control the heat that well.  It was either full on or full off.

Insurance is frustrating, I was a little ticked... They even said I had to have at least 100 feet around my house completely

cleared of any branches, scrub Oak, and whatever within 90 days or lose insurance.  Granted they didn't like my

drum heater either.   Sited my neighbor about 1/2 mile away for having mulch in their raised garden bed.

I used to work for a lumber company before I retired. That gave me a great source for wood..2x4 SYP.  Thus, I could

easily experiment and see how much wood each configuration of a RMH uses.  I could also compare this to a Wood

gasifying stove too.

[ericaus]

I wouldn't be too concerned about insurance. I ran into this problem as well when I built my 10 inch batch box. It just means that you won't be covered if your heater burns your house down. My attitude is that if anyone is stupid enough to build a heater that has the potential to burn their house down, they don't deserve to have insurance in the first place.
Just design, build and operate it safely and you won't have any problems.
I can't comment on the 100 foot perimeter you quoted. I've never come across this before. My block is heavily wooded and isn't seen as a problem.

[masonryrocketstove]

Jun 11, 2023 14:07:08 GMT -8 dwayne said:

I wish you a very good New Year.

Are you in the South American Andes? That’s the only place I’m aware of that celebrates New Years in June around this time.
Happy New Year to you, too.

I will let you go right ahead parroting internet stuff, and let you argue with a company that has a government certified RMH, and have been selling them for years.

You do know that the US gov’t EPA certification only covers emissions testing, right?

And that the combustion efficiency tests only rate the heat output while the fuel is burning in the combustion chamber, right?

And that masonry mass heaters are exempt from US gov’t testing requirements and UL labels because they provide heat even when they’re not burning, they can’t be transported to an EPA certified lab, and they can’t be tested-in-place using EPA test protocols, right?



...And you do realize that in order for the G2 Liberator to be legally sold it had to be US gov’t certified as an instant-heat output "woodstove," because it doesn’t meet the definition requirements of a masonry mass heater, according to ASTM and the international building code ...right?


That’s not internet parroting. Literally everything I mentioned above is either law or statute currently on the books, or is information cited from the 2 published books I recommended.

The Austrian government also has a lot more published info on how these systems work to meet the much higher standards they have in Europe… but it’s all in German.




Edit: here’s the info provided on Liberator’s own website: what they sell is a single burn-rate pellet stove. Their EPA certification, UL, and ASTM labels all identify it as a pellet stove, not a thermal storage mass heater. rocketheater.com/faq-1/

And even though they originally marketed it under the model name “RMH-2” and called it “The Liberator Rocket Mass Heater” as a branded model name, *not* an identification of heater type ..they have now rebranded that model and call it the “G2” because of how many people complained about their false, deceptive advertising.

Just look under their FAQ page. They say that installing their pellet stove coupled to or integrated with a thermal mass can only be done in theory and that “doing so is an unconventional installation method” ...meaning that they’re very aware it doesn’t work as mass heater ...because it’s designed as a pellet stove, which had to be certified as a pellet stove...

They’re ripping people off who don’t read the fine print, don’t understand how thermal storage mass heaters need insulated burn chambers and thermal mass to function, and are hoodwinked into thinking that their pellet stove is a “mass heater” because Liberator originally marketed it that way, using that misleading branded model name.