Hello
I am building a rocket mass heater as part of a community gardens project.
Have a few q's I need clearing up...
In the book Rocket mass heaters by Ianto Evans and Leslie Jackson it states that the gap between the heat riser and the outer barrel should be 1 1/2 inches. what is the reason for this and how important is it? I've seen some stoves where the gap looks much bigger.
-is it ok to have the bottom of the outer barrel at floor level and then cut a hole in it for the exit flue? does this make it better/worse, and why is this?
Many thanks
jim
