Glenn Herbert wrote:As short as your mass is, you would be much better served by a bell than a duct. The space formed by a 55 gallon barrel cut in half lengthwise and placed flat side down will give enough volume for the hot gases to linger and give up most of their heat. Connect the manifold exit to the bottom end of the half-barrel, and the chimney exit from the bottom of the other end of the half-barrel. The hot gases will rise and give up their heat, and only the coolest will sink and exit to the chimney.
You appear to have a good spacing under your core and mass to protect the floor from the heat.
Aaron Dailey wrote: I'm a bit nervous about working with cob since I haven't a lot of experience so I'm going to keep a close eye on the manifold or maybe just pour some concrete around it so I know it will stay sealed. I will run it full blast and take a temp reading of the manifold before I pour concrete around it to make sure the cob is thick enough that it doesn't get to hot for the concrete.
Aaron Dailey wrote:
i wanted to know if it was a real problem so i kept most of the joists untaped and have kept a co2 detector in different places around the heater and the detecter has never detected a single ppm.