Okay as promised here’s my setup for getting the most heat from my woodstove.
Extended flue with dampers. Have a look.
The three dampers slow down the products of combustion (that’s the technical term for smoke etc.) The flue gets very hot, probably hotter than the stove itself. And there is more surface area than the stove.
This whole setup is like having two stoves operating at one time, sort of. The “second stove” doesn’t use any fuel however. It just gives off heat.
One more thing of note – in the center picture, see that blue area? that’s the inside of my return air duct. A little crude, i made it from aluminum, part of an old pool. Anyway when i have a nice hot fire going, i can turn on the fan from my central heat / ac system and circulate the heat to the house evenly. By the way check the last pic. that blue tank is my water heater, and look! my oil burner. we try not to use that at all.