I'm sure it's been covered but I don't see where. Has anyone done research for burying say a 4" duct in the cob (thermal battery) to deliver heated air to a clothes dryer or perhaps a distant room that doesn't heat well by convection? A very small ducted fan could be controlled by a thermostat for temperature control. My questions are along the lines of: how long to run the duct; what diameter, (4", 6"); how fast would it deplete the thermal mass?
