Just finished reading Ianto Evans' & Leslie Jackson's book on rocket mass heaters and one question came up about the heat risers.
There's instructions on how to build a brick RMH including a brick riser and says that it must be insulated but doesn't say why...
So, why does a brick riser need to be insulated (I would have thought that the bricks themselves would be sufficient)?
The bricks are not insulative enough. You need HIGH temps in the riser to get the clean burn/re-burn. You also need a large temperature difference between the riser and barrel to "pump" the exhaust through the heat exchanger/bench.
"You must be the change you want to see in the world." "First they ignore you, then they laugh at you, then they fight you, then you win." --Mahatma Gandhi
"Preach the Gospel always, and if necessary, use words." --Francis of Assisi.
"Family farms work when the whole family works the farm." -- Adam Klaus
We've gotta get close enough to that helmet to pull the choke on it's engine and flood his mind! Or, we could just read this tiny ad:
Heat your home with the twigs that naturally fall of the trees in your yard