[oil pan 4]

I have already calculated this out.
When it's freezing out side I burn on average 4 to 5 pounds of wood per hour.
That's about 40,000 btu per hour of fuel.
If I replace that wood stove with a 100% efficient propane camping heater I run the camping heater on high at 18,000 btu per hour it doesn't get nearly as warm.
So if I start burning 1/5 the wood even at 100% efficiency that's about 8,000btu per hour. If I turn the propane heater down to low which is about 8,000 to 9,000 btu per hour it doesn't provide nearly enough heat to keep the living room and surrounding areas warm.
A rocket mass heater could probably reduce wood consumption by up to 1/3.

I am using a lot less wood now with a wood stove compared to a fire place. The wood stove provides more heat and uses 1/5 to 1/3 the wood and the heat spread out much further into the house.