Tuesday, January 31, 2012

Smallest Wood Stove and Smallest Wood Boiler

Adding some new information:
Yeaaaah!  We've found the whole load of stuff.  To find small boilers, look in the UK and Europe also, but lots of people use wood stoves in the UK, and they frequently have small houses, so there are lots of small wood stoves, and small wood stoves with what they call back boilers.
Charnwood has a distributor in NA, and their Cove 2B model could be a good size for low energy homes.
The following site lists quite a few different wood stoves with back boilers, some fairly small:

Also see:

And if you are looking for really quite a small output, the Salamander Hobbit below now has a back-boiler option (!).
Salamander is now also offering their Hobbit stove in a DEFRA -approved version and they have an even smaller stove called the Pipsqueak.

I have been getting more and more interested in the possibilities of wood stoves and wood boilers - BUT cannot find that very small, high-efficiency, sealed-combustion, direct-vent wood boiler!  This would be ideal for the occasional back-up hot water heating, and possibly snow-melting.  However, I have located a number of smallest wood stoves, some of which are beautiful!

Here are some:
http://www.salamanderstoves.com/docs/64/the_hobbit/  4kW output (14,000BTUh), $800 including delivery to NA.

The link below is really a very sweet little stove - The Thelin Gnome - it is a 16" diameter pellet stove.  Really Compact, but about $3000, I hear.
The search I do to find these things is now evolved to be 'Sailboat wood boiler', and 'micro wood boiler' and 'micro wood gasifier'. 

Here is a very cool stove for an RV or a Sailboat - made of stainless:  The Kimberly Stove:
It is about $3500, I think.

The Jotul 602 is about $1200 in the Toronto Area.
The F602 is listed at 28,000 BTU output - about 8kW - 19x11x25"h cast iron, non-catalytic clean burn 75% efficiency.  Uses room air for combustion.  Apparently there are really no direct vented wood stoves - I don't understand why.
I'm discovering there are a lot of these in the UK:
Here is the Acorn by Aarow, 4kw (about 14,000Btuh), and priced at 658 pounds.

8kW Wood Boiler available in the UK for 599 pounds.

Another one from the UK, this one priced at 539 pounds.

30,000 BTUh, 17x14x28"h including legs

http://www.marinestove.com/herringinfo.htm  This site lists three or four tiny wood stoves for sailboats.  Lovely.






http://www.blakes-lavac-taylors.co.uk/prod01.htm - Kerosene, Diesel, and Parafin heaters

A very small, 55,000 BTUh on-demand propane water heater:

An Excellent resource on heating with wood, its history and all the different types of wood burning appliances.

Ah!  Found a water heater for a jacuzzi - the CHOFU!
http://www.islandhottub.com/woodhtr.html - about $1200 from Amazon.com right now.

To convert any woodstove into a water heater:
http://www.hilkoil.com/  By the way, as far as I can tell, there are wood boiler makers using these coils such as this one:  http://nationalstoveworks.com/hotwaterstoves.html

An engineer who's built his own wood-fired cookstove/space heater/water heater.


  1. Are you sure you want to incorporate a wood burning device into a superinsulated air tight home? The thermal bridging, air leaks, and worst of all potential for carbon monoxide poisoning should make you hesitate!

    1. I was freaked out about this as well, but take a look at this: https://www.usstove.com/index.php?route=product/product&path=307&product_id=492
      - A window-mounted Pellet Stove, using a fan to circulate the hot air. No combustion gases in the room, no oxygen is drawn from the room. Yes, there are thermal bridges to the exterior.
      This is why I've been thinking all about a stove specifically designed for this situation. Air-tight, sealed combustion, direct venting - This would take care of the air-tightness issues. What can be done for thermal bridging....hmmm the insulated chimney is nothing new. Perhaps a thicker insulated chimney, with a thermal break at the wall or ceiling junction would help?
      The small sailboat-style stoves are all the heat that is needed in the Passive House. - The exhaust stack from these is only 3" diameter - but for domestic hot water, we could get away with just one of these.

    2. Moreover, gas-fired boilers are routinely installed in air-tight homes. Why not wood? I think the wood-burning appliance has a hotter chimney, which means metal construction and the thermal bridge issue. Otherwise, no different from a gas appliance.
      Even electric appliances have their issues in air-tight homes - For example, baseboard heaters easily burn/pyrolise the dust near the elements - this could be an indoor air quality issue, no?

  2. Hi Lyndon,

    here is another idea:


    they have a "nano" model which is suitable for energy efficient houses.

    it puts 20kbtu into water storage and 10kbtu into house heat.

  3. One obvious difference with between a wood burning device and a gas furnace is the need to physically deliver the fuel into the device. This requires a door that must open easily and yet seal reliably again, and again, and again. It may be possible, but if heat reason for the device is heat, I would think a few electic heating elements buried in a concret slab would be sufficient (and would not be exposed to dust).

    However, if wood burning is an aesthetic preference (for example you want the ambiance) then go for it but be aware of the implications.

  4. Hi,
    My husband and I are building a Passive House in CT and we're going to have a wood stove also. I've done a tone of research, don't let people talk you out of it, lots of super insulated houses, as tight as passive houses, have wood stoves, and some Passive Houses too. If you decide you want an outside air intake (there's alot of debate on whether this is a good idea, evan among passive house consultants) I would consider Hearthstone and Rais. They both have direct sealed outside air. You have to be careful, there are two types of outside air intakes. The most common comes in under or behind the firebox and mixes with the room air ( it is not sealed, not what you want in a Passive House) the other kind connects directly to the firebox and room air is completely eliminated. I talked to Morso and their outside air connections are not a direct sealed connection, which is to bad because their stoves are very nice and a bit less expensive. We went and looked at Hearthstone and Rais, Rais seems to have the tightest seal on the doors ( stick a dollar bill in the door, shut it and try to pull the bill out). Rais was also very helpful about providing details about how long the pipe could be and how many elbows. 15 ft, no more than 3 elbows. They even have stoves that only come with outside air. Good Luck with your house!

    Some helpful links


  5. The wood boiler is the way to go green on your house and cut down on the monthly energy bill. The principle of a wood boiler is simple and use wood or pellets as fuel, in order to produce heat. It an excellent alternative to standard oil, electric or natural gas heating. Thanks a lot.

  6. ChimneyHeaters.com Chimney Heat Exchanger.I also have the toyo stove and that combined with one of these Heat exchangers will heat a 2000 sq/ft House to the point that you have to open the windows in winter.

    I got mine at Chimneyheaters.com but I am sure there are of lots of places that have them.

  7. These boilers are good. But they will require space, that is why more people refer tankless water heaters.

  8. There are several factors which you need to take into account when you're searching for the best wood stove for your home. Learning these would help you choose which one would be effective for your needs.

  9. Thanks so much for sharing this. I too was in search for something to heat up the house a little bit. The good thing about a wood boiler is that they are very cost efficient and energy efficient.

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  15. Hello

    Regarding the Salamander/Hobbit stove from the UK - did you manage to install it? If so, how did you work through certification of the product? It currently does not have CSA certification.