Saturday, May 22, 2010

Starting a rocket stove thermal mass heater

Its getting cold in Canberra. The fire place in our house is smokey and cold. The gas heating is too easy and expensive. Its time we learned how to build a rocket fire!

I discovered rocket fires last year when Permaculture Keith blogged about them. That lead to a couple of Youtube videos, which lead to meeting Erica and Ernie in Portland Oregon to see one in action.

Since that visit, Sunshine and I have been busy selling our house in NZ, moving to Australia, and having a baby. Now in a rental, its difficult to commit to a full build, but I've found a bit of time to study the method.

Basically, a rocket stove thermal mass heater is a super efficient wood fuel heater that can be built by just about anyone, using waste and/or easily collectible materials. To give you an idea, in Dunedin we used an efficient and certified wood burner that used about 4-6 cubic metres of wood per year. Erica and Ernie told us they use about 1-2 cubic metres in their rocket heater, and their house was less insulated than ours!

If you want to get a sense of what a full rocket stove thermal mass heater is, this is a great introductory video:

Here's the book that the video refers to.

And here's a really good illustration by Erica, of the critical design of the rocket stove. At that link are a series of photos documenting a full build, including the thermal mass heater.

Here's another photo documented installation with some adaptations to the standard design, by Michael Blaha.

And I started the Wikipedia article to see where it might go.

My attempts so far
So begins my attempts to study and learn this technique for heating. After the usual terrible time trying to source materials in Canberra, here's a series of videos of my first mock up.

That same playlist is also on my Youtube channel.

Canberra is an incredibly difficult place to find anything online. The websites are crappy and the search results are worse. As a result, sourcing materials is frustrating. All we needed was some short lengths of steal pipe at varying diameters, a few steal drums of varying sizes, about 10 fire bricks, and 10 normal bricks. So I baled the family into the car and drove around looking for word of mouth. The main waste recycle facility was useless. We found private waste recycle yards that looked promising, but were all locked up with no one around. Everyone we spoke to directed us out to Fyshwick, the industrial hub of Canberra. There we found some materials, but all set at exorbitant prices :( It seems what useful materials is recycled, is pretty well stitched up by business. But we did manage to scrape together a few bricks and some guttering just to get this first mock up made.

The hunt for better materials continues... and the dream it to connect up a boiler and Green Steam Engine.


Minhaaj said...

Actually we use that same here in Southern Sweden countryside where i am. Not sure if thats exactly that but its a stove powered by wood but lots of air ventilation and angles to learn. Other than that the water-based heating system is amazing too. With radiators and pressure pumps it was quiet exotic to learn.

Michael said...

Wow - the efficiency of that thing sounds incredible!? Franzie's mum builds very similar looking wood heaters here in Germany, but I don't think they use the combustion chamber - and so I guess are not the same... I'll have to show here and ask her about it!

Leigh Blackall said...

Yes, a Swedish friend here says they are similar too. I think the key differences here are:

1. Anyone can build this with waste materials.
2. The horizontal exhaust driven by the rocket heat rizer.

The Chinese have been heating thermal mass benches for a long time, but again, not with a rocket fire system.

If you guys find illustrations of the systems you have seen, it would be great if you could post here the links.. these rocket mass heaters are pretty new innovations based on old techniques. It could be that the old techniques have lost their explanations, and so have become needlessly specialised. Perhaps these rockets will bring back conviviality to people... I hope they will for us :)

katty said...

I love the big stove specially because i like to cook all kind of recipe, how ever i prefer to have a reasonable place. Actually i saw a beautiful stove in a house that was published in costa rica homes for sale it was big and beautiful, i think i will go there because it catched my attention.