I made a new RMH this past weekend. Below are my specs followed by my questions:
---I should have all the dimensions correct for the core (H1, H1.5, H3 according to the Wisners).
---The core and riser are made of new, clean firebrick with a thinset of clayslip as recommended.
---5.25 X 5.25 dimensions for the square inches in the core's channel.
---6" duct system, 20' long in mineral soil bed for my attached greenhouse.
---Exhaust vents out the side of the greenhouse.
---Starts up no problem and exhaust moves through the system and ducts wonderfully. However...
The RMH does not heat up like I had hoped. It just gets warm, not hot, and does not convert fully to steam and CO2.
One possible problem: The distance between the riser and the top of the barrel is 2-3", not the recommended .25 of the 6" system which would be 1.5 inches.
QUESTION: How critical is the distance between the riser and the barrel an issue as per the riser getting hot enough to burn the smoke?
The riser is coated in a clayslip-perlite mixture with further insulation of 2 inches of perlite encased in sheet metal.
QUESTION: Does a new, wet RMH need a curing process before it becomes an "adult dragon"?
I've fired up this thing only once thus far. Just one time, so I'm thinking of trying it again before I dismantle it and start all over.
Many thanks to all who might respond to these questions.