Rocket Mass Heaters

A rocket mass heater is a clean-burning, high-performance burner usually put together using a majority of recycled and/or natural materials, such as cob. Owners claim an 80-90% reduction in wood usage compared to heating the same space with a metal wood stove.

Rocket Mass Heaters: The Basics

As opposed to the masonry heater, which requires some advanced masonry skills, the rocket mass heater can be built by any enthusiast with basic masonry and engineering abilities. The only problem with this project is difficulty in getting a building permit, because basically not many officials know what a rocket heater is.

The exception is Portland, Oregon, which has a building code for rocket mass heaters, thanks to Ernie and Erica Wisner, who share some hints on how to acquire a permit on their site. Many communities do have building codes and give permits for masonry heaters, so you might need to treat your rocket heater as a masonry heater. Be cautioned, that without a permit, you may void your fire insurance policy.

Rocket Mass Heaters: How They Work

The rocket mass heater works on similar properties as a masonry heater. A fast, high heat and oxygen-fed fire burn up the volatile gases and particulates, leaving very little pollution, and turning almost all the fuel into energy. A bit of smoke is released during the first minutes of a fire, until the temperature in the chamber is hot enough to burn the combustion gases as well as the wood.

The major difference between a masonry heater and a rocket, is that the rocket stove has an insulated J- or L- shaped combustion chamber that forces the fire to burn horizontally. The fire then hits a 90 degree angle at the end of the chamber which causes a strong turbulence to rise up the insulated heat riser, creating a strong draft that feeds the intensity of the fire.

The heat riser sits inside a barrel or larger secondary chamber which extends a couple of inches above the inner riser. The hot rising gases hit the top of the secondary chamber, give off some of their heat and then fall down the larger chamber’s sides. The exhaust is then directed through flue piping, usually set within a bench, which will absorb the last vestiges of heat.

Today’s rocket heaters often employ cob, but there is no reason why you can’t build a masonry bench of brick, stone or tile. The final flue gas that escapes the exit is basically water vapor, as hydrogen during combustion turns into water vapour.

Small pieces of wood, basically trimmings from one’s yard, can be used to fuel the heater. The spaces between the small pieces of wood allows more draft into the combustion chamber, helping to fuel a fast, hot fire.

Rocket Mass Heaters: Examples and Plans

france

Rocket mass heater. Leaving the drum exposed allows immediate heat to enter the room. Covering the barrel with a natural surface of cob slows down the instant heat and holds heat for slower release. permaculturedesign.fr

bec-touviere-roket

Rocket Mass Heater in a straw bale home in France by Bec Touvière. Courses given once a year in France. Great video of the process at bottom of page here: permaculturedesign.fr

rocket-stove-google.jpg

Rocket mass heater, built during a Bioconstruyendo held in February, 2010 in Patagonia, Argentina, in a straw bale and adobe cabin. www.firespeaking.com

juured.ee

Rocket Mass Heater by
Juured in Estonia.

rocket-mass-heater1

Rocket Mass Heater by Ernie and Erica Wisner. Plans for sale here: ernieanderica.info/shop

nicodermus

The combustion chamber runs horizontally, the flames and gases hit a 90 degree angle and then throw off a lot of strong turbulence, which helps intensify the heat and create draft, or a rocket effect up the heat riser. The heat riser is usually a smaller pipe set within a larger pipe, the inner heat riser needs to be insulated as that creates a heat differential which again increases draft.

This heat riser is then usually set within a 55 gallon barrel, with the top exposed to give off instant heat, but there is no reason it could not be set within masonry. (See resource below.) The barrel’s lower half is often covered in cob, to store the stove’s heat and allow the heat to radiate slowly.

rocketheater-ernieanderica.info

Rocket heaters need a heat riser that is at least twice as tall as the burn tunnel is long. From: Rocket Mass Heaters by Ianto Evans, Leslie Jackson.

rocket-mass-heater-belgium

Rocket mass heater and cooktop in Brussels. Great design! Brick veneer and must be a refractory cement counter top. See the inner workings here: flickriver.com

rocket-mass-heater-brussels

Rocket mass heater and cooktop in Brussels. Wood goes into feed to right of the sink. Cooktop is to right of the feed. See the inner workings here: flickriver.com

ernie-and-erica

Rocket mass heater by Ernie and Erica.
ernieanderica.blogspot.com

rocket-stove

Rocket mass heater in a Shamen center in France. From “Rocket stoves, wood fires and mass heaters” ecologie-pratique.org

rocket-heater-juured.ee

Rocket Mass Heater by
Juured in Estonia.

rocket-mass-heater-2

Rocket mass heater in
Cob Cottage, Coquille, Oregon, the home of the creator
of the Rocket Mass Heater, Ianto Evans.

poele-de-masse

Rocket mass heater mostly used for cooking as it is in the highlands of Guatemala. joachim2010.blogspot.com

terre-et-flammes-fr

Mass Heater by terre-et-flammes.fr

le-poele-de-masse-01

This is a masonry mass heater but looks like a nice start off point for a design of a rocket mass heater. poeles-eco-09.com

new-stove-rocket

An antique stove was surrounded in cob. The wood loads on the right side, there is a heated bench behind. By Ernie and Erica Wisner, more photos: plus.google.com

poules

Rocket mass heater with a cooktop. The heat riser does not have to be a barrel, but can be built from masonry. marquedeposee.over-blog.com

homestove02

Rocket mass heater by expert Kirk “Donkey” Mobert, sundogbuilders.net, donkey32.proboards.com

rocket
systemed.fr

dragon heater

Dragon Heater’s 6″ powder coated metal rocket heater. Kit includes everything but the 55 gallon barrel and the perlite. It can be operated on its own or connected to thermal mass storage. Inside the red box is a 6″ Dragon Burner. A square feed tube and 2″ round air intake. The barrel has been painted with Stove Bright Hi-temp paint in black metallic. Available in 4 colors, textured black, copper vein, silver vein, and red. $1450. www.dragonheaters.com

Rocket Mass Heater How-To Videos

How To Build A Rocket Mass Heater

Metal Heaters

The Best Books About Rocket Mass Heaters

Stoves

Affiliate Policy (full policy): Posts may contain links to outside vendors that pay us a commission when you purchase from them, at no additional cost to you. Thank you in advance for supporting our site.


Author: keiren

Keiren is an artist who lives in New York City. A lover of animals, nature, science & green building.

Add comment

E-mail is already registered on the site. Please use the login form or enter another.

You entered an incorrect username or password

Sorry, you must be logged in to post a comment.

26 comments

by Oldest
by Best by Newest by Oldest
1

These look so stylish! And surely they're pretty efficient as well, as gas prices are going up, this is certainly a good alternative!

2

These designs are great! Check out http://www.dragonheaters.com for rocket heater cores.

3

Hi Guys, hello from South Africa, I looking for some help in building a rocket heater here but cant afford the book 🙁 Need to know a couple of details etc. Anybody out there?

Thanks

Neil

4

Great site, looks like Ill be back to get some great ideas

Thanks

Neil

5

very encouraging and informative .planing on using some of the ideas in my 30'x90' poly tunnel will send u pictures if u guys would love that one love

6

You can get a core already made at dragonheaters.com Makes the building process much easier

7

What's the the smallest size RMH that can be used and still be efficient, I'm trying to make as small of a square foot design or small foot print As possible. Can I make it tall and thin? In maybe 3x4 foot area?

8
Construction Dorset

Good write-up, I am regular visitor of one's web site, maintain up the excellent operate, and It's going to be a regular visitor for a lengthy time.

9

My mother-in-law walks naked in the house now that I finished their mass heater. The central air just is not as warm feeling, it is dry feeling. Also it is cheaper to heat to a higher temp, and that is why that wrinkled old bag has gone nude like in the old country.

10

I'm curious if there is any way to somehow add an out mesh like screen about 3-5 inches away from the exposed barrel that would help keep kids/pets from touching it and getting burned. with some sort of small latch door so you can still get to the barrel if need be. I have a cat and some day would like to add kids to the mix. ..I'm just not sure if the exposed areas will be safe enough.

11

Hi Lauren, Or you could cover most of the barrel in cob, like the second photo from the top. And then put some woobly piece of metal atop so the cat will quickly learn not to jump up. Or the mesh as you say....I will keep my eye out for any examples. Best!

12

I love rocket heaters. Right now I only have an iron parlor stove for my little cottage but one day I want one of these. I've never seen so much eye candy on one web page before. Beautiful heaters!

13
Andreas lunyalalo

cute heater, i have to try one.

14
Theodore Sawer

This is my first discussion board entry at this point.! I am pleased to be obtaining associated in this article and since I am new to discussion board neighborhood, I really feel occasionally, that I've to understand a whole lot, believe you fellas have patient on me.Thank you see you guys

15

Hallo,

I like so much this rockets and I want to make one by my self. I have some questions if it is possible to get answers:

1. Can I use the old vent to take the smoke out. It is about 6 m long. And I intend to make a 3 m long bench.

2. The hole for in take air it is so necessary? In Ianto Evans book I did not see mentioned. If yes it can be a regular small door? I can use the same kind of door for the ash cleaner place?

3.The third door it should be on the and of the bench? It can be the same with the other ones? Or should be something with very good close up?

16

I have a hot water boiler that feeds baseboard units. I want to remove the unit and build a rocket stove from a hot water tank to heat the water instead. Can I connect the water lines (cold, hot, return) to the water tank?

17

Hi, Please check out the permies.com forum on rocket stoves...so much info there and so many who can definitely answer your questions!

18

Sorry, this link is lost, i'm veryinterested.

RMH with bread oven, step by step photos:

19

I am building a webpage about this solution for the problems we have with natural gas in the north of Holland.

More and more earthquakes are breaking houses, but nobody is thinking of a soultion.

Rocketstoves are. Keep up the good work.

20

Would love to make the stove. DON't look to hard!

21
Outdoor Heaters Sydney at Premium Patio

Outdoor heaters are the only way to provide warmth, and the best way of increasing comfort for outdoor

social areas of any size.

22
Mike Patterson

Hi! Very interested in this technology. For home use it would seem that the home would provide combust ale air thereby decreasing overall efficiency. Is there a system that uses outside,air?,would this increase efficiency? Thanks in advance,

23

The most attractive examples, I think, are finished in white.

What exactly is the white finish coat on those RMH's?

Thanks. I really enjoyed this page!

24

The picture labelled 'Rocket mass heater in a cob cottage in Eugene, Oregon' is actually located at Cob Cottage in Coquille, Oregon and is the home of the creator of the Rocket Mass Heater, Ianto Evans.

25

Thanks so much for that info!!!

26

Howdy, thanks for the informative site. Just providing a direct link

to the book Rocket Mass Heaters, by its developer: Ianto Evans.

http://www.rocketstoves.com

Cheers!