A (green)way of heating our home
Some years ago I tought about using a simple masonry stove as a heat supply to boil water, and heat my home. All kind of aspects started to emerge as I went on forward with ideas related to surfaces, and materials which last longer when exposed to flames continously for longer periods of time. The first and easiest way to heat water was from the first step, to use a water-tube system, actually a water circuit heated by a water-tube heat exchanger. After I saw the oxidation and short lifetime of copper tube exposed to flames, I went for, and used 1.1/4' steel tubes. O.K., but how to do it in an enclosed space of 15x50x100 cm space, available in my already existing masonry stove, which can't be drilled out for pipes to feed the heat exchanger from below, but only from above. The answer was, to use a 1/2' diameter, 1 meter long pipe(same length as the large 1.1/4' one), put it into the large one and feed water trough it, right to the place where the flames were the hottest, at the end. So the lowest point on the 1.1/4' pipe is welded and tested to be watertight. To evacuate hot water I used a T junction and some other junctions to form a 4 piece pack of double tubes. These junctions allow distribution of water in the 4 inner tubes, and collecting the hot water from the outer tubes. The system was fitted with a thermo-manometer, a 2.5bar safety valve, a 8liter expansion tank, a thermostat fitted to one element and a recirculation pump, which drives water into the radiators.
***Important!
-the system needs to be aired out
-the pump speed should be tested to make sure that there is no uneven heating of elements in
the heat exchanger.
-pressure needs to be monitored at the peak of the process, make sure that there are no losses
-starting the fire needs to be intense, to avoid creating creosotes and deposits on the heat
exchanger
*This heating method works, it is modular, and can be extended! I'm using it, and consumes a small amount of wood. Outside temperatures are -12 degrees Celsius!!!