Mini Wood Stoves

hobbit-stovegc2reddit-logoOff the keyboard of Geoffrey Chia

Follow us on Twitter @doomstead666
Friend us on Facebook

Published on the Doomstead Diner on January 29, 2016

KimberleyStove

Discuss this article at the Doomsteading Table inside the Diner

It's not Rocket Surgery: choosing an indoor mini wood stove

Geoffrey Chia, Jan/Feb 2016

 

As of 25 January 2016 at the time of commencement of writing this article, the cold spell affecting East Asia killed more than 65 people in the subtropical island of Taiwan. The temperature in Beijing dropped as low as minus 40 degrees C, however Northern China is used to dealing with heavy snow dumps and subzero temperatures in winter and hence coped better compared with Taiwan. The last time snow was seen in Taipei, the capital of Taiwan, was more than a century ago. The fact that Taiwan is a relatively small subtropical island, which we would expect to be dominated by the moderating effect of the South China Sea, makes this rare event seemingly even more bizarre. That is, until you understand the physics of how coastal and island provinces on the leeward (downwind) side of continents can often be dominated by continental rather than maritime weather, which I mentioned in my previous article "Location, location, location", where I compared Vancouver Island with Nova Scotia.

It is no coincidence that a record breaking monumental snowstorm also affected the East coast of the USA, the leeward side of the North American continent, at the same time as the cold weather affected East Asia. In general, at those latitudes; the windward (Western) sides of the continents, which are more dominated by maritime influences, are less prone to extremes of heat and cold than the Eastern sides.

Climate scientists tell us the peculiar combination nowadays during Northern winters of high temperatures in the Arctic regions and low temperatures extending to low latitudes, is due to the disruption of the circumpolar jet stream as a consequence of climate change.

One issue I did not mention in my "Location" article was the beneficial warming effect of the Gulf Stream on North Western Europe. The demise of the Gulf Stream appears to be a foregone conclusion as climate change progresses, following which North Western Europe can expect even worse cold spells in winter, even as the rest of the world heats up.

My "Location" article focused on avoiding heatwaves and managing fresh water supply. It did not discuss coping with cold weather (which well prepared humans can survive better than heatwaves). In choosing our future location, it is far better to settle where there will be low risk of heatwaves (despite the occasional cold snaps), rather than to settle where there will be low risk of cold snaps (but have high risk of terrible summer heatwaves). Most locations in our future world will face the latter situation in due course.

InStove60&100litreModelsThis article will focus on one item which can keep you comfortable in cold weather, especially when faced with the inevitable fossil fuel shortages in the near future: the indoor wood heater/stove, with special attention to the secondary combustion biomass (SCBM) heater/stove. It is not a comprehensive article but will concentrate on models which can be used in a caravan or tiny house, my particular area of interest.

The other important role of this biomass heater/stove will of course be for cooking. It will become an essential appliance when we face future shortages of kerosene and LPG.

Before we proceed, it is vital to mention the first three principles in dealing with cold weather: insulation, insulation, insulation (just as the first three principles in managing electricity use are efficiency, efficiency, efficiency). The well insulated tiny house, warmed by two people and a dog, may not require any additional heating because of the small interior volume of air.

Furthermore, in my particular tiny house design http://www.resilience.org/resource-detail/2544932-building-a-tiny-house, I incorporated an indoor steel water tank (under the lounge seats) which will provide thermal mass superior to (and lighter than) concrete.

Good insulation, small interior volume and thermal mass (heated by daytime passive solar influx) alone may enable you to go without active heating for most of the year, depending on where you live.

LiberatorHeaterOn the other hand, for adequate ventilation and to avoid condensation, it is necessary to allow some fresh (cold) air in and stale (warm) air out of the tiny house. In the case of the hermetically sealed modern Scandinavian dwelling, this is achieved (with minimal temperature drop) by a heat recovery ventilation system. For a less airtight dwelling in a less cold climate, sufficient ventilation may occur through "natural" leaks in your house (eg air coming in via the gap under the front door and out via a poorly sealed upper window), which will of course cause a drop in internal temperature. If you are installing a wood stove in your tiny house for future cooking anyway, this stove can double up as your heater and there will be no need for an electrically powered heat recovery ventilator. In this article I use the terms biomass and wood interchangeably, because 99.9% of the time, most of us use wood for our (non fossil fuel) stoves.

My criteria for the ideal biomass stove / heater for a tiny house are as follows:

  1. Must have exhaust flue / chimney – absolutely essential requirement

  2. Minimum use of fuel

  3. Minimum emissions

  4. Small and light

  5. Little need for constant tending

  6. Ability to monitor fuel and flame

  7. Able to source air intake from exterior

  8. Affordability

  9. Other issues eg aesthetics

Jotul(1)Criteria 2 and 3 can be summed up in one word: efficiency. The least efficient, most hazardous, most polluting and most wasteful heat source is an open fire. Next worst is the open brick fireplace. The standard cast-iron combustion box with flue is a good deal better but still woefully inefficient. Furthermore even a "small" cast-iron stove can easily weigh 150kg, which is quite unsuitable for a tiny house on wheels.

Even though the technology has been around for decades, we have failed to widely embrace the secondary combustion biomass (SCBM) stove, of which the "rocket stove" is the commonest design. Standard fires only burn the primary solid material of the biomass, releasing secondary combustible materials such as soot, hydrocarbon gases and carbon monoxide into the atmosphere, which can cause acute irritation of the airways and eyes, even poisoning or asphyxiation. If inhaled chronically over decades it can lead to emphysema and even lung cancer. These remain terrible problems in Third World countries. A stove designed to burn both primary biomass as well as the secondary emissions is far more efficient, causes far less pollution and is thus far healthier than traditional wood stoves. It needs far less fuel to do the same work (eg just a quarter of the wood normally used for a conventional stove), hence requires less back breaking physical effort chopping and carrying wood, hence also protects against deforestation. Additionally such a stove can reach much hotter temperatures. There have been great initiatives to introduce SCBM stoves (such as the InStove) for use in the developing world, if only for health reasons.

Bobcat-Rocket-StoveIf you google "rocket stove", the vast majority you find will be solely for outdoor use and will lack exhaust flues. Even those with exhaust flues may not be certified for indoor use (the commercial forces of our fossil fuel economy have long suppressed this market). Hence most "permies" these days are pioneering this option without official sanction.

Development of the "rocket mass heater" actually preceded invention of the rocket stove. This mass heater is a different beast, in that the hot metal components are enveloped in big heavy slabs of cob (or similar earthen or concreted thermal mass) to retain the heat for slow and steady release even after the fire goes out. The cob can be shaped in the form a comfortable warm bench. If used indoors, this mass heater is only suitable for a large, fixed, ground based dwelling, not a tiny home on wheels. Furthermore many rocket mass heaters may not incorporate a stove in their design.

With regard to SCBM stoves with exhaust flues/chimneys (which may or may not have been officially approved for indoor use) my websearches revealed the following types:

WEBSITE http://www.instove.org/60-100-liter-cookstove http://www.rocketheater.com/ http://www.bobcatrocketstove.com/ Unfortunately no longer in production
Size and weight Probably too big for most boats/caravans Probably too big for most boats/caravans Small (perhaps too small) and light
Need for constant tending +++
horizontal fuel port needs constant feeding
++
vertical fuel port, wood self feeds by gravity as it burns down
+++
small horizontal firebox needs regular feeding
Ease to monitor flame and fuel Easy Easy Need to open door periodically
Ability to source external air intake Maybe, but need to custom configure No ?probably yes
Cost in US dollars $850 for 60litre, $995 for 100litre ?$1500 (contact dealer) Unavailable
(?previously $400)
Remarks Mainly designed as a stove to cook for large numbers of people, cooking slots only fit custom sized pots Mainly designed as a heater. Sides of secondary combustion chamber can get very hot & pose risk of burns Add-on small water tank can provide thermal mass and hot water supply
Aesthetics Utilitarian Industrial Odd looking, may appeal to some

————–

WEBSITE Silverfire Hunter Stove Kimberley Stove/Heater
Size and weight http://www.silverfire.us/hunter-chimney-gasifier-stove https://www.unforgettablefirellc.com/
Need for constant tending Small and light Ideal size for boat/caravan
Ease to monitor flame and fuel ++
"batch feed" wood vertically
can burn slowly overnight without tending
Ability to source external air intake Need to remove pot to view status of wood and flame The only SCBM stove with viewing window
Cost in US dollars No Yes
Remarks $220.00 $3750 – 3995
Aesthetics When starting, large flames with smoke leap out of central combustion chamber. Pots and pans get coated with soot from primary combustion By far the most expensive but also the best made
  Looks like a biscuit tin Classy

The above are mere impressions obtained from web searches, not based on any practical experiences of mine. Practical reviews from the manufacturers and customers can be found from amazon.com or youtube. This article is intended to spark (pun intended) interest in this topic so that the reader can do their own research and make their own decisions. One issue I have not yet looked into is the maintenance required for each stove type. Every setup will require periodic cleaning of the chimney.

silverfirehunter stoveBased on size and availability, the only two SCBM contenders for use in a tiny house on wheels are the Silverfire Hunter and the Kimberley stoves. Although the Kimberley is far superior in every way it is also hugely more expensive, however you generally get what you pay for. It is false economy to buy a cheap stove if your house ends up burning down.

The Silverfire Hunter is described as a "toplift updraft" or TLUD gasifier. It generates bare flames and smoke out of the central cavity at startup (secondary combustion occurs later in a ring around this). This issue may be a dealbreaker for the indoor user. During cooking, the base of the pot/pan is in direct contact with the primary flame, causing soot deposition. An optional cast iron disc cover is available to minimise this, although it will also reduce heat transfer. One reviewer wrote that it needs frequent ash removal which requires it be disconnected from the flue, taken outdoors and turned upside down.

For those still keen on mini wood stoves of standard design, the following review websites are helpful:

http://www.tinywoodstove.com/small-stove-reviews/

http://www.waldeneffect.org/blog/Smallest_wood_stoves/

As mentioned previously a small standard cast iron stove can easily weigh 150kg, however the tiniest models may weigh less than 25kg.

For tiny house purposes, two particular models seem especially suitable (mainly because I greatly value the ability to source external air intake):

Jotul 602: apparently more than a million of these have been made, hence one would expect all the bugs have been ironed out by now. H25.25” x W12.6” x D21.25” , costs around $900. Weighs 73kg, able to configure for external air intake. Apparently 75% efficient (?capable of some secondary combustion)

The Salamander Hobbit stove: http://salamanderstoves.com/the-hobbit-stove/

Size: 302mm wide, 272mm deep and 465mm high, the low emission version costs £525 pounds sterling.

Weighs 60kg, able to configure for external air intake. It is designed to enable some secondary combustion, although not as efficient as the purpose designed SCBM stoves.

 

CONCLUSION:

As in all things, your choice will depend on how you weigh up the various advantages versus disadvantages, as well as your individual circumstances. Many amateurs have cobbled together home-made rocket stoves for outdoor use, however few sane people will hazard home-made stoves for indoor use.

 

G. Chia Jan/Feb 2016

 

 

 

 

 

 

 

 

 

 

2 Responses to Mini Wood Stoves

  • Stoveman says:

    Great article.  Also check out the incredible Pacific Energy secondary combustion stoves, made in Denman on Vancouver Island, British Columia.  The smallest model "Vista" with the lowest wall clearances is designed for a house trailer and completely heats our 720 sq foot small house on 2 cords per year.  http://www.pacificenergy.net/products/wood/traditional-stoves/vista/

  • tagio says:

    Another great article by Dr.Chia!  Thanks,RE. I am sure Dr. Chia is busy with his cardiology practice, but man it would be great if he put a book together about his approach to off grid living and resiliency.  He seems to have thought about it quite a bit and in a very practical way.

Knarf plays the Doomer Blues

https://image.freepik.com/free-icon/musical-notes-symbols_318-29778.jpg

Support the Diner
Search the Diner
Surveys & Podcasts

NEW SURVEY

Renewable Energy

VISIT AND FOLLOW US ON DINER SOUNDCLOUD

" As a daily reader of all of the doomsday blogs, e.g. the Diner, Nature Bats Last, Zerohedge, Scribbler, etc… I must say that I most look forward to your “off the microphone” rants. Your analysis, insights, and conclusions are always logical, well supported, and clearly articulated – a trifecta not frequently achieved."- Joe D
Archives
Global Diners

View Full Diner Stats

Global Population Stats

Enter a Country Name for full Population & Demographic Statistics

Lake Mead Watch

http://si.wsj.net/public/resources/images/NA-BX686_LakeMe_G_20130816175615.jpg

loading

Inside the Diner

https://qz.com/1577986/the-boeing-737-max-crisis-goes-way-beyond-software/An aerial photo show...

Quote from: Eddie on Today at 09:08:49 AMFirst off, I didn't make the videoNo you didin't, you put it up for review by the Diners, and said it caused you to rethink your opinion of social democracies.  The aut...

Quote from: AJ on Today at 10:15:12 AMEddie,I agree with you. If we could have jettisoned about 75% of the military/spy budget we could have extended the safety net to include free healthcare and education. None of thi...

Eddie,I agree with you. If we could have jettisoned about 75% of the military/spy budget we could have extended the safety net to include free healthcare and education. None of this will work going forward into collapse.AJ

Quote from: RE on Today at 12:06:03 AMhttps://www.npr.org/2019/03/22/706073410/stocks-indexes-drop-as-bond-market-fl...

Diner Twitter feed

Diner Newz Feeds
  • Surly
  • Agelbert
  • Knarf
  • Golden Oxen
  • Frostbite Falls

Quote from: Surly1 on March 21, 2019, 03:35:00 AMD [...]

Doomstead Diner Daily March 21The Diner Daily is a [...]

Doomstead Diner Daily March 20The Diner Daily is a [...]

Doomstead Diner Daily March 19The Diner Daily is a [...]

I'm a fan of your example if not always a fan [...]

Quote from: UnhingedBecauseLucid on March 18, 2019 [...]

CleanTechnicaSupport CleanTechnica’s work via dona [...]

QuoteThe FACT that the current incredibly STUPID e [...]

The Syrian National News Agency headlined on Febru [...]

Good to know you're still alive. [...]

My Dear Diner Friends, Have received your messages [...]

Alternate Perspectives
  • Two Ice Floes
  • Jumping Jack Flash
  • From Filmers to Farmers

The Apology: From baby boomers to the handicapped generations. by David Holmgren Re-posted from Holm [...]

Society Is Made Of Narrative. Realizing This Is Awakening From The Matrix. By Caitlin Johnstone Orig [...]

But We Need the Eggs Re-posted from Epsilon Theory   Ben Hunt of Epsilon Theory is one of those rare [...]

About That Liberal Media.... By Cognitive Dissonance   Charts and Info from Business Insider   I dis [...]

Perhaps It’s Time to Believe the Impossible By Cognitive Dissonance     "Alice laughed: "T [...]

Event Update For 2019-03-21http://jumpingjackflashhypothesis.blogspot.com/2012/02/jumping-jack-flash-hypothesis-its-gas.htmlThe [...]

Event Update For 2019-03-20http://jumpingjackflashhypothesis.blogspot.com/2012/02/jumping-jack-flash-hypothesis-its-gas.htmlThe [...]

Event Update For 2019-03-19http://jumpingjackflashhypothesis.blogspot.com/2012/02/jumping-jack-flash-hypothesis-its-gas.htmlThe [...]

Event Update For 2019-03-18http://jumpingjackflashhypothesis.blogspot.com/2012/02/jumping-jack-flash-hypothesis-its-gas.htmlThe [...]

Event Update For 2019-03-17http://jumpingjackflashhypothesis.blogspot.com/2012/02/jumping-jack-flash-hypothesis-its-gas.htmlThe [...]

With fusion energy perpetually 20 years away we now also perpetually have [fill in the blank] years [...]

My mea culpa for having inadvertently neglected FF2F for so long, and an update on the upcoming post [...]

NYC plans to undertake the swindle of the civilisation by suing the companies that have enabled it t [...]

MbS, the personification of the age-old pre-revolutionary scenario in which an expiring regime attem [...]

Daily Doom Photo

man-watching-tv

Sustainability
  • Peak Surfer
  • SUN
  • Transition Voice

A Home in the Sea"African female elephants dropping tusks may be an epigenetic adaptation similar to Surfers Ear [...]

Zombie-fiIled Death Ships"Each passenger’s carbon footprint while cruising is roughly three times what it would be on la [...]

Cheerleaders for Doom"Exaggerated is in the eye of the beholder." I just finished reading David Wallace-Wells’ [...]

Seizing Defeat"In our moment of ultimate defeat as a species, a spark has been kindled."Hans-Peter Schmi [...]

Non-stick Pans and Sticky Memes"We have, through accident or design, structured the human ecology into a zero sum game, where [...]

The folks at Windward have been doing great work at living sustainably for many years now.  Part of [...]

 The Daily SUN☼ Building a Better Tomorrow by Sustaining Universal Needs April 3, 2017 Powering Down [...]

Off the keyboard of Bob Montgomery Follow us on Twitter @doomstead666 Friend us on Facebook Publishe [...]

Visit SUN on Facebook Here [...]

To fight climate change, you need to get the world off of fossil fuels. And to do that, you need to [...]

Americans are good on the "thoughts and prayers" thing. Also not so bad about digging in f [...]

In the echo-sphere of political punditry consensus forms rapidly, gels, and then, in short order…cal [...]

Discussions with figures from Noam Chomsky and Peter Senge to Thich Nhat Hanh and the Dalai Lama off [...]

Lefty Greenies have some laudable ideas. Why is it then that they don't bother to really build [...]

Top Commentariats
  • Our Finite World
  • Economic Undertow

Not even Einstein or Hawking -- let alone some unheard-of gentleman by the name of Godfree -- can de [...]

Why did the Aztecs thoroughly merit extermination? Because they did things like ripping people' [...]

Hi Steve. I recently found what I believe is a little gem, and I'm quite confident you'd a [...]

The Federal Reserve is thinking about capping yields? I don't know how long TPTB can keep this [...]

As some one who has spent years trying to figure out what the limits to growth are. let me say that [...]

Peak oil definitely happened for gods sake. Just because it isn't mad max right now is no indic [...]

@Volvo - KMO says he made some life choices he regrets. Not sure what they were. And I don't th [...]

RE Economics

Going Cashless

Off the keyboard of RE Follow us on Twitter @doomstead666...

Simplifying the Final Countdown

Off the keyboard of RE Follow us on Twitter @doomstead666...

Bond Market Collapse and the Banning of Cash

Off the microphone of RE Follow us on Twitter @doomstead666...

Do Central Bankers Recognize there is NO GROWTH?

Discuss this article @ the ECONOMICS TABLE inside the...

Singularity of the Dollar

Off the Keyboard of RE Follow us on Twitter @doomstead666...

Kurrency Kollapse: To Print or Not To Print?

Off the microphone of RE Follow us on Twitter @doomstead666...

SWISSIE CAPITULATION!

Off the microphone of RE Follow us on Twitter @doomstead666...

Of Heat Sinks & Debt Sinks: A Thermodynamic View of Money

Off the keyboard of RE Follow us on Twitter @doomstead666...

Merry Doomy Christmas

Off the keyboard of RE Follow us on Twitter @doomstead666...

Peak Customers: The Final Liquidation Sale

Off the keyboard of RE Follow us on Twitter @doomstead666...

Collapse Fiction
Useful Links
Technical Journals

Growing global food demand and security concerns dictate the need for state-of-the-art food producti [...]

We show that oceanic cycle lengths persist across oceanic cyclic time-series by comparing cycles in [...]

Rising temperature, drought and more-frequent extreme climatic events have been predicted for the ne [...]

Most weather and climate models simulate circulations by numerically approximating a complex system [...]

Crop yields are strongly dependent on the average climate, extreme temperatures, and carbon dioxide [...]

Follow on our http://www.doomsteaddiner.net/forum/