hello instructablers!

i am about to start building a rocket stove. I am loking for information on how long does it take for the wood to get burned, but i cannot find anything. I know that it depends on the kind of wood i will use, on the dimentions of the opening that the air is sucked from,on how big is the stove., etc

I need to know aproximately how often your oven need to be refilled with an average hard wood. I would like to heat a space with that system but i would like to do other things at the same time and not have in mind of the stove to be refilled too often.. Does anyone have an idea aproximately about those times?