I was on the website for a Swedish cabin and “barn-house” company named Arvesund, and noted that one of their traditional hunter’s cabins had a spiffy setup: a cast iron stove/kitchen with cook burners, and a stainless steel water tank with spigot that wrapped around the stovepipe, looking almost integral with it. And I thought to myself, I want one. Bad.
We do not like propane dependency in the slightest, and the idea of wood-heated hot water is very appealing to us. We have a propane stove and water heater out of necessity at this time, but we would love to move away from those when we can. We chose to have a wood stove (a Jotul 602) as well as the option of electric heat for many reasons, but control over where our energy comes from is one of them. The establishment tells us wood-heated houses “Are bad for the environment,” “Wood is a scarce resource and burning it pollutes the air,” and “Wood heating is inefficient,” and about wood-heated water systems that, “They aren’t safe.” We thought, what have people done for thousands of years to heat their water? And what happens in a forest fire? And have you checked where we live? We supply lumber to the world – what would be better than using wood that grows here, and returning the ashes to where it was grown? Isn’t that completing the life cycle better than anything you would do?
In answer to the statement “wood heating is inefficient” I would agree that the way we commonly burn wood in the U.S. is. Most Americans are unaware that the way we burn wood now is not the best or even the traditional way, merely the easiest-to-sell way. And if they are aware of the former, they assume there must be a very expensive, over-engineered catalytic woodstove that is the answer. There is no awareness of how woodstoves work, or don’t, as it were. However, the masonry-heater, kachelofen, kakelugn, hypocaust, or rocket-stove (versions of the same thing) that has been used since Roman times is so efficient that the air that exits your house is barely warm, and invisible because all of the gases were completely combusted. Those hand-built stoves are the old way – burn the wood so hot that even the volatile gases (smoke) burn, and store that heat in a thermal mass – tile, stone, cob, water, etc.so the heat is not lost, but slowly radiated back, in the form of conductive heat, the best kind for heating people. Of course, as with life, the answer is not so simple as burn wood, without thinking, as much as you like. Wood-burning fits in well with passive solar and heavy insulation as part of the solution. I see the drawbacks to wood for heating your house or your water as: you have to use your head when heating that way – it is not idiot-proof. You can burn yourself, asphyxiate, destroy your water-heater, set things on fire, or melt them if you don’t know what you are doing. You have to live in an area with many trees to make it ecologically sound. Ideally, you burn your wood as close to 100% efficiency as possible, and with all things tiny-living, the stove should perform more than one function to justify its space. But I can only assume that the reason we are told, in the Pacific Northwest of all places, that wood heat is bad, is out of ignorance, belief that we are stupid, or because they would rather sell us something than have us be self-sufficient. I suspect it is a mixture of all three.
Well, a masonry heater is awesome and I would totally have one in a tiny cabin if that’s what we were building, but thermal mass is heavy. Water is too, but you can drain it out of your house when you move it. Most wood-fired water heaters rely on an existing water tank system to work, which we don’t have (not even a 6 gallon RV one – we went tankless). I looked and looked at Arvesund’s catalogue, and could find no mention of these beautiful tanks or wood stoves. So I emailed them, the annoying American. They were very helpful: Harvia makes the tanks, a Finnish company that manufactures saunas and associated gear. The tanks run around $400, so we will probably wait to buy one until fall. But we have a local Harvia dealer, so we could acquire one easily.
So our current solution to the heating/water heating problem is: use our Jotul 602 but line it with firebricks to insulate the firebox and thereby increase the temperature of combustion to make it more efficient, and capture that extra heat escaping up the stovepipe in the form of mobile thermal mass – a water tank, wrapped around the stovepipe, that we will use for bathing and dishes. And when we don’t feel like dealing with a fire, we use electric heat. Here she is, fresh from the Harvia website:
This beauty holds 22 liters, measures 14″ w x 16″ h x 7.5″ d and her pipe inlet measures approximately 4.5″. Made entirely of stainless steel. Joy! Anyone have one that can comment on performance?