Rudy Mallonee : Yes it can be done and the technology already is in common use in various other systems, however any system that takes heat off of a thermal mass by blowing air past it, has to have a ductwork designed large enough to deliver air at a slower speed of moving air as the temperature in the Thermal mass drops!
A clear example of this happens in the running of an air to air Heat
Pump, This type of system does not try to match the temperature of the delivered air stream of a Fossil Fuel Fired Furnace as measured at the 'heat register' due to the best efficiency curve Electrical
energy in / heat energy out, which can obtain a 1 : 3 ratio ! Instead a lower temperature, higher volume of air is flowed more slowly through the duct work delivering the same number of therms/B.T.U.s per minute as is delivered by the fossil fuel fired furnace. - again, just in a larger volume of delivered air.
I think the Heat Pump with its matching ductwork would be a better match for The Rocket Stove, than a Fossil Fuel Fired Furnace, but even that combination would require a back up energy source,
OR some one dedicated to feed the
Dragon in your Rocket Stove small meals over a 3-4 hr period at least once a day to generate/store 20-25 hrs of heat and do it 24/7/365, well not 365, how about using the heat pump, again that 1 : 3 ratio, to bring it down to 24/7/90 ? You are not eliminating a Furnace, you are
Adding One or Two
At one time Heat pumps were designed with a thermal control that varied the flow of air, delivering warm but cooler air at a slightly slower speed to prevent complaints of 'my system is blowing cold air' this feature was being phased out the last I knew, just going to electrical heat and fossil fuel fired back-up systems !
Again blowing cool air over a Thermal Mass to pick up heat that is itself variable, will require a variable control due to the lower temps radiated off of the thermal mass,
OR back-up heat. Taking heat off of the 55 gall drum will only require the use of a secondary fan limit switch, and back up heat. You will still need a blower motor rated for operation in higher temps or other secondary fan/blower motors!
While this system could be built and used 'off grid ' due to triple redundancy it would not be cheap, not much chance of seeing a payback !
All this is a very,very long way of describing the problems in trying to make a " Space Heater '' into a whole house Furnace ! Three long and lusty cheers for the crew that can make it work ! I hope this builds on what you were saying and fills in some gaps ! Pyro-Allen L.