posted 6 years ago
It sounds to me like you're looking for all the benefits of natural gas or propane, but from wood.
I am a huge fan of wood, but even if you're growing fuel wood that is calorically dense enough to do what you're doing, the physical properties of wood are going to be the limiting factor. The single best wood-fuelled option I have come across that doesn't require near-constant monitoring and at least daily feeding is a worm-screw feed pellet stove or furnace, whereby you load a giant hopper beside the furnace with pelletized wood, which is fed in small quantities into the burn chamber, where it burns at an optimal temperature before more are added.
I can't think of a wood-fired appliance that could be used as you're indicating without also being a huge fire risk, at least to itself. I mean, what does the feed system look like? Or does the half-week's worth of wood sit stacked on one side of the burn chamber to what, slowly slide in as it burns? What ensures it doesn't all burn?
Have you looked into Rocket Mass Heaters? They have the benefit of mass as thermal battery, such that the fire can burn hot, the wood and associated gases burn completely for a short time, and the mass traps the heat for slow release. If you haven't, do look into them. Also worth looking at are other masonry-based solid-fuel appliances that occur in different iterations from Russia all across northern Europe, and across the whole temperate world.
My concern, and it resonates with yours, is that a slow-burning fire will be, of necessity, a low-temperature one, increasing the generation of incomplete combustion products, including tar and soot. A single, high-temperature burn with something to capture the heat and release it slowly, or in the case of the pellet stove, a continuous small fire at the correct temperature for complete combustion, are both far superior to a soot-belching, tar-leaking low-burn.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein