Some videos showing recent work in the shop. The first two are for a masonry heater that I am building and the last one is a prototype for an improved firebox door for the barrel oven kits.
In our quest to live smartly and well, Eva and I have resisted the urge to use an electric dryer to dry our clothes. Although this common appliance certainly offers some conveniences, it seems a gratuitous use of electricity and energy that is otherwise available to us in free and smart ways. We had been getting along alright hanging our clothes out in the sun during the warmer months and hanging them on expandable accordian-style wooden racks near our heating stove in the colder portion of the year. With the arrival of our new-born daughter and the prospect of many loads of cloth diapers to wash and dry, I figured it was time to up the anti and improve our system or else succumb to the need for an electric dryer. I wanted to build a drying rack that was retractable to the ceiling so that it wouldn’t take up any floor space. This turns out to give it the added benefit of placing it up in the warmest part of the house and exposes all the clothes equally to this rising, circulating hot air.
Watch the video to see more details about how it works.
|2||2 x 4 (x8′) Lumber||1.39||2.78|
|8||1/2″ x 48″ Hardwood Dowel||1.58||12.64|
|4||1 1/2″ Wall/Ceiling Mount Pulleys||9.49||37.96|
|3||2″ Wall/Ceiling Mount Pulleys||10.99||32.97|
|4||1 1/4 Pulley Swivel||3.49||13.96|
|4||1/4 SP Anchor Shackle||1.89||7.56|
|1||6″ Rope Cleat||3.99||3.99|
|2||Twisted Nylon Rope 1/4″x100′||16.49||32.98|
Other great resources:
I have just posted this article about recent research on rocket mass heaters to Hand Print Press with this same title. It is a synthesis that I have been wanting to write for some time since the experiences at the MHA gatherings have been so rich. I’ve wanted to make sure that others could benefit from the research and discoveries that we have been making there.
Here is the Article’s Table of Contents to give you a sense of it:
- The Difference between Rocket Stoves and Rocket Mass Heaters
- The Book on Rocket Mass Heaters
- The MHA Experience
- Construction Processes with Commentary
- Rocket Mass Heater Build at WildAcres 2009
- Masonry Rocket Mass Heater at WildAcres 2010
- Impromptu Rocket Mass Heater at WildAcres2011
- Some Links for Further Reading
We built this wood-fired oven in Bali for Max’s parents using local bricks, clays, sands and fibers. The oven joins the traditional paon (cookstove) that Max built a few years ago.
This oven features ample wood storage for both units, a metal firing door and a wooden door for baking. (Stay tuned for an article about firing doors and efficiency in wood-fired ovens.)
It is always a fun challenge to apply our knowledge of ovens and natural building to local materials. The clay for this oven comes from a village roof tile factory scrap pile and the sand and stone came from a nearby volcano. We found an incredibly porous lava stone to insulate underneath the hearth floor and surrounded the oven’s thermal layer with a mixture that included rice hulls and thatching grass.
Note the sand used to make the smooth inside shape and the sculpted “squirrel tail” to jog the chimney. Upon finishing the oven, we cooked for a three day “Live-Culture Cuisine” fermentation workshop led by Sandor Katz and Mary Jane Edleson.
Many delicious feasts ahead!
This heater was built for a family who live near Eugene, OR. It features a see-through firebox, heated bench and a bake oven. The outside skin is laid with Montana Bitterroot ledge stone with Three Rivers stone detailing the bake oven arch. We cast, poured and and polished the bench which includes special embedded stones and fossils.
The heater has a compact, responsive design which serves as a partial wall between living and dining room spaces. It could have many different facing looks, occupies an area of 48″ x 48″ and stands 6 1/2′ tall.
- What is a masonry heater?
- See other heaters in our portfolio
- Join our mailing list to receive updates on projects and workshops
Thanks to Greenleaf Design Build for their good organization and excellent
craftsmanship which allowed our work to flow together seamlessly with their’s.
From: Max Edleson max (at) firespeaking.com
Date: Sat, 3 Dec 2011 07:52:43 -0800
Subject: Re: [MHAmembers] member news
Indeed, Alex, the article you have written is great and this area of research you are pointing to is very exciting.
The issues you bring up are excellent. I would like to try to add to what you have written.
As far as advantages of the rocket stove, the idea for those inclined to do things themselves to be able to build their own heating system without too much expense and without too many necessary tools is one that is very exciting – one that ignites a passion. The relative simplicity of the rocket stove design with few specific and basic parameters, allows for a great deal of customization and flexibility in design which is also very exciting and often practical when placing a heater into a space and further fuels the doers interest and passion in building it.
The particular combination of immediate heat at a usable rate and stored heat at an impressive rate of accumulation is also an area that the normal rocket mass heater design really shines in.
The bench is a wonderful aspect of the design. Both from a comfort standpoint of being able to sit your butt and back on soft, penetrating heat and also from a social perspective. I think most of us who have experienced the benches from the last couple of years at Wild Acres have experienced this.
Novelty also always has its appeal, at least to a certain sector of society!
But then there are many significant disadvantages, most of which you have pointed out. The subfloor: the rocket mass heater, as developed by Ianto Evans, evolved from experimentation in cob buildings where the heaters are built on grade (on some combination of compacted earth, gravel, and sometimes an adobe-like subfloor). Similar to the conditions of a concrete slab on grade that is found in many garages, for example. So you have a nice, solid, load-bearing floor that is also non-combustible that you can spread your design out on. This is essentially the opposite of how most homes are built in north america: light, lofted, insulated and combustible floors. This point, as you point out, ends up being pretty essential to design considerations as an on-grade subfloor generally would suggest the possibility of letting a heater’s design spread out while a joisted wooden floor with a foundation coming through the middle of it tends to suggest a more compact layout to minimize the size of the foundation and related expenses (especially in a retrofit).
Also, as you say, the user experience of a rocket stove can be summarized as finicky, at best. I have seen several rocket stoves that have been the core of people’s homes and worked very well day in and day out. I have seen others that worked ok and I have seen a surprising amount that don’t work so well or at all. The flexibility of design, the do-it-yourself style and, significantly, the fact that many I have seen were built in very-rushed workshops leads to an unpredictability that is often difficult to diagnose once things are sealed up if they don’t work. This can be very challenging.
Also, general rocket mass heater design so far has under-emphasized the importance of cleanouts, particularly in bench designs with bends in them. It is a process to remove the barrel and re-seal it, if and when this is necessary. And a plastered cob bench can require significant maintenance, at least bi-annual.
So, all these things have left me also in search of incorporating the advantages experienced from rocket mass heaters with all of the experience and advantages that comes from masonry heater building.
One note on hardware and expenses. I have come to realize that the door is the significant technnology that fundamentally distinguishes open fireplaces from masonry heaters. eg., that reduces the amount of air entering the combustion chamber so that it can not only be efficient but also be throttled in such a way that the combustion and long tail of combustion can be guided through the much longer channels of a masonry heater. This is probably both obvious and often overlooked. The door, especially metal doors, are a relatively new technology in the long history of fireplace building man(and woman)-kind. Perhaps one of the most significant contributions of the rocket stove is to accomplish this reduction of air into the combustion chamber without a door. It does this so successfully that you can even burn the fire upside down as we have experienced. The ideal amount of air is that which generally fits between the split burning wood. A brick is often used to close off excessive air if the firebox is not completely full of wood. This last element, for example, is critical and an example of the very important fine-tuning that is happening in a rocket mass heater burn.
At the same time, this is a very important design limitation since it prohibits sizing up the firebox without important repercussions. Those who were observing may have noticed us “barefoot builders” during wildacres 2009 really experimenting with this aspect. When we re-built the rocket mass heater inside that was eventually plastered with the lime we had made and painted with a naked lady (yes, that one!) we had built the front in such a way that we could make different fireboxes. If you remember, we tried putting a small glass door on the front of the down-draft firebox but found that even this slight modfication in widening the firebox to accomodate the glass door meant that the wood did not stay as organized as it needed to and, I think, allowed more air in than was necessary, especially when the firebox was not completely packed with wood.
As I have begun to experiment with making doors, I have come to appreciate doors a lot more and the care and cost involved in either casting or fabricating them. I have also come to think that in temperate to cold climates, firebox doors should really be thought of as a family heirloom and at the center of a family’s wealth – after all, there are times in history when money isn’t worth much more than paper for starting a fire which people in different parts of the world have experienced in inflationary situations like I experienced in Argentina and that I’m sure people in Russia have experienced. I don’t think that people consider the expense of either a vehicle, a computer (pillars of modern life) nor for kitchen appliances in a remodel in the same way they do masonry heater/cookstove hardware and the other related expenses. This may just have been my previous bias coming through to though I think it reflects the current moment and society’s related values.
One more thought before I get out into the cold to organize rock from a mountainside into some semblance of a beautiful heater skin. The issue of code. As I have begun to work building heaters in more code-respecting(/code-enslaved) situations, I have had opportunity to reflect on both its advantages and disadvantages. The only, main and significant advantage of code that I understand is that it ensures safety and formalizes that responsibility between the builder and the people living in the home, especially where this relationship is mostly otherwise anonymous. It also ensures a standard of quality to some degree by ensuring that things are done in a certain way and that certain materials are used.
On the flip side, I have come to understand that the whole issue of building codes and inspections has a lot to do with counties and other jurisdictions ensuring that what you build in your home not only serves you, but really more importantly, someone who you either might like to sell your house to or someone who would like to buy your house (hopefully under favorable conditions). While I can see the benefits of this, I get that uncomfortable feeling that in this situation, as with property taxes, it is really the county that owns your house and what you do with it… and I don’t think this is so conducive to really connecting with one’s home and where one lives.
There is also that element of stilting forward evolution.
These comments, especially the last ones, should be taken with a grain of salt. Most of this is to say, yes!, very exciting what you have written and propose Alex!
We built this masonry heater in the Portland area in autumn of 2011. Our clients had collected many beautiful bricks dating back to 1883 (a long time from our West Coast perspective!), local basalt rock, and cobble stones that originally paved the streets of Portland.
This masonry heater (based on the Swedish 5-run design) has a see through firebox, a bake oven, a three-sided heated bench, and a place for wood storage.
This project brings together our understanding of the technical aspects of combustion and heating efficiency and our experience with design and use of recycled building materials. The heater is currently curing and the exit flue will be installed shortly. We plan to update this post once the heater is fired and make new posts about the process of this build and about the use of polished “concrete counter tops” for benches and other elements of mass heaters. Check back on this site, join our mailing list, and see more about this project on Facebook.
Thank you to Norbert Senf and Doug Hargrave for their development of the Norccore and for generous technical assistance in preparation for this project. Thank you also to Jerry Frisch for continual support and inspiration.
- What is a masonry heater?
- Other masonry heaters we have built
- Excellent DVD about natural building!
- The wonderful wood-fired barrel oven!
This Barrel Oven’s maiden voyage fed over 70 people with amazing pizzas!
The pizza above is one of Astrid’s special recipe- corn, mozzarella and gorgonzola.
Once out of the oven it is topped with arugula and white truffle oil.
Another pizza sauce was made with capers from Paolo’s mother’s garden in Italy.
I made chocolate truffle brownies and gingerbread cake for dessert!
During the party we cooked some pizzas directly on the
pizza stones and some on metal pans.
The pizzas cooked on the stones had a more crispy and delicious crust.
Above you can see the barrel oven with plaster still drying.
A good part of the month of August has been dedicated to the research, development and construction of a small multi-functional masonry heater I have been calling “The Cabin Stove”. Eva and I have both been working as instructors in the first year of the Sustainable Shelter Workshop Series at Aprovecho Research Center in Cottage Grove, OR. The building that is the focal point for this course has been designed to be just slightly smaller than the legal requirements for permitting so that it can at the same time be a teaching tool as well as a laboratory for a basic building system that a group of associated natural builders in the Pacific Northwest considers to be a sound and ecological way of making a home.
The challenge of the design of the Cabin Stove was to come up with something that was very compact but also still resembled and functioned like a masonry heater. The design criteria included heating the small space, an efficient and clean fire, utility for cooking, heating water, combining some quick/immediate-releaseheat with slower retained radiated heat, relative ease of construction, not too expensive, aesthetically pleasing, and being as compact in size as possible. A very interesting process to try to combine all of these together.
Our test firings of the prototype in our shop were very promising. The fire burned well and had no problem making its way through the longer pathway, even notably when the door was open with the beautiful cast fire screen reducing the overall air intake to a moderate amount. I think the design meets most of the criteria listed above well with the exception possibly of cooking utility since this was compromised to accommodate other features.
For the initiated, it is basically a very compact J-loop contraflow with a bi-pass that runs directly to the flu and allows it to function even as an open fireplace. Rather than insulating the top of the heater as is done often in masonry heater construction, there is a 1/4″ steel plate placed on top that serves as a cooktop and source of immediate heat. I am optimistic that the proportion of immediate and retained heat will be a good one for our bio-region where temperatures can fluctuate greatly during the day and from one day to the next. We are within but on the outer limits of the kind of climate that masonry heaters were designed for which explains the need for continued development and innovation.
I did notice in firing the prototype that the big steel plate I had placed on it arced noticeably when hot so I welded a 3/16″ frame onto the Cabin Stove we built at Aprovecho though I am quite sure that the heat will play its funny games and have its own way with the final shape of the steel plate. Cast iron is almost certainly the way to go for the top although I do not know of a source of affordable custom sizes.
Although the heater at Aprovecho was designed to be a double-skinned heater with a compressed earth block and local stone veneer, I am very excited that we will first test the heater with a single skin. A neighbor has offered to lend his carbon-monoxide and air-quality monitors to test whether there are any dangers that result from expansion cracks in the single skin. Given our climate in Oregon, the prospect of building responsive single skin heaters is a very interesting one. (Note: the variation in the firebrick is because we used firebrick out of an old heater that had been taken down. The students re-milled each brick to cut away the old mortar to return the brick close to original dimensions).
I have recently been very inspired by the Open Source design philosophy so I share the rest of these photos of process in that spirit! Stay tuned for more on this heater and other research and endeavors. Click to see any images enlarged.
You can see some other details of the building, including one of the timber frame’s posts; the faswall and stone stemwall; and strawclay insulation packed in between Larsen-truss style framing.
Details of Hot Water Serpentine. More on Plumbing for Thermosiphoned Hot Water Systems….
The light and surrounding forest were really exquisite when I took these shots of the veneer material. The compressed earth blocks were made by the students.
Find out more…..
The Masonry Heater Association of North America has recently developed the HMED (Heater Mason’s Education & Development) program designed for masons and people interested in learning how to build wood-fired masonry heaters.
The program is designed to:
- Provide an education program that starts with basic information and skills training.
- Provide a standard curriculum that will be delivered in facilities throughout North America.
- Provide opportunities to earn continued education credits for various certification programs.
- Promote safe building practices for everyone interested in building masonry heaters.
- Establish a training system that is specific to North America.
MHA’s HMED program provides an excellent opportunity for someone to learn the basic theory and construction of masonry heater, a necessary step before taking on the task of building masonry heaters. The program was developed due to increasing interest in Masonry Heaters as an alternative method to heat homes.
Classes are currently scheduled for:
September 17 – 20, 2011 in Perth, Ontario, Canada, level one, modules 1 &2
November 04 – 07, 2011 in Shutesbury, Massachusetts, level one, modules 1 &2
September 17 – 20, 2011 in Perth, Ontario
$399/module for MHA members
$450/module for non MHA members
November 4 – 7, 2011 in Shaftesbury, Massachusetts
$399/module for MHA members
$450/module for non MHA members
$500 room and meals at Sirius Community
What are Masonry Heaters?
A masonry heater is a special type of fireplace made of stone, brick, stucco or tile which will heat your home safely and comfortably. Masonry heaters burn wood, which is North America’s cheapest and most abundant bio-fuel. We currently use less than ten percent of available deadfall timber from our forests. Masonry heaters burn efficiently and with very low emissions, which make them extremely “green”.
Masonry heaters work on the principal of thermal storage due to the considerable thermal mass of the materials used in their construction (most of them are heavy, often weighing tons). The best masonry heaters soak up most of the heat from the wood blaze within the firebox through a cleverly designed system of channels or chambers which “harvest” heat from the hot gases as they pass by. This energy migrates through the masonry slowly until it reaches the surface where it “illuminates” the room with invisible rays of heat known as infrared radiation. This way heat from a fire in the morning can still be warming a home in the evening.
The Masonry Heater Association of North America hosts an annual workshop where masons can get hands-on practice building wood-fired masonry heaters and bake ovens. Instructional books on how to build and operate masonry heaters and bake ovens are available on the MHA’s website.
For more information on masonry heaters, education classes or membership in the Masonry Heater Association of
North America, contact the MHA office:
Find out more…..