4 ms·

These are a fore-bearer of the masonry heater. Very similar to what some off-grid types have built and called a rocket mass heater. Very interesting principle b

These are a fore-bearer of the masonry heater. Very similar to what some off-grid types have built and called a rocket mass heater. Very interesting principle but unfortunately (or fortunately if you are so inclined) they will never compete with the ease of operation of a gas (or oil) central heating system.

toss1 8y ago
... as much as there are issues w/oil & gas heat, reverting with wood would for the current population would quite quickly deforest the planet, not to mention be more polluting (especially particulates). Design for efficiency, solar collection into a thermal mass, etc...
- black6 8y ago
  Coppicing and pollarding are sustainable methods of producing wood for rocket mass heaters, which operate best with kindling-sized sticks of wood. Rocket mass heaters are extremely efficient. The wood undergoes almost complete combustion and particulates are not a concern.
  - KirinDave 8y ago
    It's worth noting a good rocket heater will have similar properties to a wood gassification system, which people may recognize as powerful enough and light enough to run converted service vehicles in the tail end of WW2.
  - pbhjpbhj 8y ago
    Kindling is the very smallest pieces you start a fire with - are you really supposed to use mm sized pieces? Coppicing would not be useful for that, unless you're heavily processing the coppiced wood first?
  - pjc50 8y ago
    We use a lot of energy. Last time I ran the numbers I estimated that if the Drax wood-fired plant used UK wood rather than Canadian wood it would consume every tree in the country within a year. 750k tonnes/year: https://www.drax.com/sustainability/one-company-helped-transform-biomass-business/ https://www.drax.com/sustainability/one-company-helped-trans...
    - greglindahl 8y ago
      Drax looks like it generates electric power, not heat.
KirinDave 8y ago
Well, what's an interesting question about these systems is, "In a modern context where we understand science much better and have much more sophisticated materials available, could we use these principles?" The real trick here is using available materials for heat storage, using air convection to circulate heat but not waste gas, and tightly limiting oxygen flow to make the most of minimal materials. It's definitely not bad, from an efficiency standpoint, to be compared to rocket heaters. They're still some of the most efficient systems we have.
- adrianN 8y ago
  We could probably improve the dimensions quite a bit if we used something other than granite for heat storage. Something that changes phase, like in those pocket warmers, would probably be more effective.
  - yetihehe 8y ago
    There is fireclay [1], and I have fireplace with several bricks made from it. When fired in the evening for 2-3h, will keep warm until morning. [1] https://en.wikipedia.org/wiki/Fire_clay https://en.wikipedia.org/wiki/Fire_clay
- xenadu02 8y ago
  “High efficiency” water heaters and furnaces use similar principles to this (and the glazed tile oven mentioned). A winding network of passageways to get maximum contact with the flue glasses and thus extract as much heat as possible. By contrast a traditional straight chimney wastes a lot of heat by dumping it outside.
  - Retric 8y ago
    That can be a feature in the summer when you wanted to cook inside.
    - Yetanfou 8y ago
      I cook on a wood-burning stove year round. Here in west-Sweden it can get quite warm in summer (with last summer being an extreme example with a maximum of 37°C and a period of around a month with daily temperatures between 25°C and 30°C, we did most of our cooking outside on an electric plate as open fire was prohibited due to the extreme drought). When firing the stove just for cooking I use quick-burning wood (spruce, fir, etc) and it doesn't really add that much heat to the kitchen, the thing is quite efficient. Come the colder months I light the stove a bit earlier, using heavier types of wood (birch, elm, oak, etc). I have yet to fell a living tree for either the stove or the heating stove (which, between the two of them, heat the whole house) as every year there is enough windfall to keep up with the demand (between 3 and 5 cubic meters of split wood per year). Felling, hauling, cutting and splitting wood is about 2 weeks of exercise per year, it is the fuel which keeps you warm twice - once while harvesting, the second time while burning it. Yes, this might be more work than just flicking a switch, touching a zone on an induction cooker (which I used before I moved to Sweden) or turning a knob but it is more reliable, more sustainable, more useful and more fun than the alternative (electricity).

toss1 8y ago

... as much as there are issues w/oil & gas heat, reverting with wood would for the current population would quite quickly deforest the planet, not to mention be more polluting (especially particulates). Design for efficiency, solar collection into a thermal mass, etc...

black6 8y ago
Coppicing and pollarding are sustainable methods of producing wood for rocket mass heaters, which operate best with kindling-sized sticks of wood. Rocket mass heaters are extremely efficient. The wood undergoes almost complete combustion and particulates are not a concern.
- KirinDave 8y ago
  It's worth noting a good rocket heater will have similar properties to a wood gassification system, which people may recognize as powerful enough and light enough to run converted service vehicles in the tail end of WW2.
- pbhjpbhj 8y ago
  Kindling is the very smallest pieces you start a fire with - are you really supposed to use mm sized pieces? Coppicing would not be useful for that, unless you're heavily processing the coppiced wood first?
- pjc50 8y ago
  We use a lot of energy. Last time I ran the numbers I estimated that if the Drax wood-fired plant used UK wood rather than Canadian wood it would consume every tree in the country within a year. 750k tonnes/year: https://www.drax.com/sustainability/one-company-helped-transform-biomass-business/ https://www.drax.com/sustainability/one-company-helped-trans...
  - greglindahl 8y ago
    Drax looks like it generates electric power, not heat.

KirinDave 8y ago

Well, what's an interesting question about these systems is, "In a modern context where we understand science much better and have much more sophisticated materials available, could we use these principles?" The real trick here is using available materials for heat storage, using air convection to circulate heat but not waste gas, and tightly limiting oxygen flow to make the most of minimal materials. It's definitely not bad, from an efficiency standpoint, to be compared to rocket heaters. They're still some of the most efficient systems we have.

adrianN 8y ago
We could probably improve the dimensions quite a bit if we used something other than granite for heat storage. Something that changes phase, like in those pocket warmers, would probably be more effective.
- yetihehe 8y ago
  There is fireclay [1], and I have fireplace with several bricks made from it. When fired in the evening for 2-3h, will keep warm until morning. [1] https://en.wikipedia.org/wiki/Fire_clay https://en.wikipedia.org/wiki/Fire_clay
xenadu02 8y ago
“High efficiency” water heaters and furnaces use similar principles to this (and the glazed tile oven mentioned). A winding network of passageways to get maximum contact with the flue glasses and thus extract as much heat as possible. By contrast a traditional straight chimney wastes a lot of heat by dumping it outside.
- Retric 8y ago
  That can be a feature in the summer when you wanted to cook inside.
  - Yetanfou 8y ago
    I cook on a wood-burning stove year round. Here in west-Sweden it can get quite warm in summer (with last summer being an extreme example with a maximum of 37°C and a period of around a month with daily temperatures between 25°C and 30°C, we did most of our cooking outside on an electric plate as open fire was prohibited due to the extreme drought). When firing the stove just for cooking I use quick-burning wood (spruce, fir, etc) and it doesn't really add that much heat to the kitchen, the thing is quite efficient. Come the colder months I light the stove a bit earlier, using heavier types of wood (birch, elm, oak, etc). I have yet to fell a living tree for either the stove or the heating stove (which, between the two of them, heat the whole house) as every year there is enough windfall to keep up with the demand (between 3 and 5 cubic meters of split wood per year). Felling, hauling, cutting and splitting wood is about 2 weeks of exercise per year, it is the fuel which keeps you warm twice - once while harvesting, the second time while burning it. Yes, this might be more work than just flicking a switch, touching a zone on an induction cooker (which I used before I moved to Sweden) or turning a knob but it is more reliable, more sustainable, more useful and more fun than the alternative (electricity).