Chris-PA
Where the Wild Things Are
This is a great example of how using the wrong terms leads to confusion. Look at the units on the numbers and pick the ones that relate to the characteristics that are important to you.
Setting aside installation, modification and operation issues for the moment - Spidey is primarily concerned about output power, and then wanting to maintain that output rate over a long time period (i.e. average BTU/hr over a several hour period). Efficiency is irrelevant. His secondary combustion stove had a high peak output rate, and it can (eventually) extract more of the energy from the load of wood, but it has a period of lower output rate once the secondary combustion period ends. That was unacceptable to him, so he threw out the coals (which represented a significant amount of energy contained in the original fuel load) while stove was still working on extracting the energy from them and loaded more wood. This reduced his efficiency below what a cmapfire-in-a-box would do.
As he's been told many times, the stove had an insufficient long term rate of energy output for what he wanted it to do, and the install having insufficient thermal mass to store the energy during peak outputs made that worse. As did his unwillingness to make any air adjustments during the burn, and the modification to turn it into a "furnace" where the only heat transfer mechanism (to the house) was by convection/air flow - that pretty much eliminates thermal storage of the heat to smooth out peaks & valleys in the output rate, as air has a low thermal mass.
Add in the expectation of a high, constant temperature in the house and what you need is a whopping big firebox smoke dragon - this gives a lot of stored energy in the fuel load, and the ability to extract energy from it at a high rate over a several hour period with no adjustments. It will lose more of the original energy available in that fuel load up the stack compared to a secondary burn stove of identical fuel capacity (i.e. less efficient in terms of total energy extracted from the fuel), but it may maintain a higher output rate during the whole burn. Basically, it won't be able to extract as much energy from those coals because it will burn them up faster, extracting energy from them at a higher rate and sending more of the energy stored in them up the stack. And then they are not in the way when you add more wood.
Others of us use our stoves differently, have different expectations and different installations. Also, we don't have the same ideological mind blocks causing us to become distracted by the need to fight the forces of evil whenever we see the letters "EPA", thus allowing us to look at a stove more clearly.
Setting aside installation, modification and operation issues for the moment - Spidey is primarily concerned about output power, and then wanting to maintain that output rate over a long time period (i.e. average BTU/hr over a several hour period). Efficiency is irrelevant. His secondary combustion stove had a high peak output rate, and it can (eventually) extract more of the energy from the load of wood, but it has a period of lower output rate once the secondary combustion period ends. That was unacceptable to him, so he threw out the coals (which represented a significant amount of energy contained in the original fuel load) while stove was still working on extracting the energy from them and loaded more wood. This reduced his efficiency below what a cmapfire-in-a-box would do.
As he's been told many times, the stove had an insufficient long term rate of energy output for what he wanted it to do, and the install having insufficient thermal mass to store the energy during peak outputs made that worse. As did his unwillingness to make any air adjustments during the burn, and the modification to turn it into a "furnace" where the only heat transfer mechanism (to the house) was by convection/air flow - that pretty much eliminates thermal storage of the heat to smooth out peaks & valleys in the output rate, as air has a low thermal mass.
Add in the expectation of a high, constant temperature in the house and what you need is a whopping big firebox smoke dragon - this gives a lot of stored energy in the fuel load, and the ability to extract energy from it at a high rate over a several hour period with no adjustments. It will lose more of the original energy available in that fuel load up the stack compared to a secondary burn stove of identical fuel capacity (i.e. less efficient in terms of total energy extracted from the fuel), but it may maintain a higher output rate during the whole burn. Basically, it won't be able to extract as much energy from those coals because it will burn them up faster, extracting energy from them at a higher rate and sending more of the energy stored in them up the stack. And then they are not in the way when you add more wood.
Others of us use our stoves differently, have different expectations and different installations. Also, we don't have the same ideological mind blocks causing us to become distracted by the need to fight the forces of evil whenever we see the letters "EPA", thus allowing us to look at a stove more clearly.
