Peter van den Berg wrote:
Personally, I once tried a top gap of 4' and the thing kept working like a charm. Couldn't get any higher since the ceiling wasn't any higher, a practical top limit probably doesn't exist.
Peter van den Berg wrote:You are right Max, although for an 8" J-tube system that would probably be 4 barrels on top of each other. That would require a high barn or something like that to reach that upper limit.
Sounds interesting to me, anyone who like to have a tower batchrocket like that?
Eight inch system, stacked barrels only. Calculating 1.5 m² for each barrel totals up to 6 barrels, 0.89 cm high each. A tower of 5.34 meter (17.5 ft) high, twice as much as my former workshop heater!
Would be really exiting to run such an appliance, don't you think?
Mark Tudor wrote:Ianto Evans' RMH in the library (Myrtle) at the Cob Cottage Company has the exhaust going out of the wall around 6 feet above ground, and has an elbow on the end to point it down to avoid the rain, and help prevent a breeze from causing a back draft. It looked like galvanized ducting, certainly not insulated double walled, but it goes through a cob wall and has a good overhang above.
While a tall chimney that extends above the roof ridge will help get a really good draw, it's not always necessary and if expense is an issue, you can always try it through the wall as high up as you can go. If you have problems with that, you can make adjustments later as well.