A fire heats the stove pipe, which then radiates heat into your home through convection. In order for this process to be as efficient as possible, you should install an insulated flexible metal chimney liner from the appliance up and out of the house. This will also ensure that air is pulled in towards the burning fuel instead of being pushed by it – making sure that all wood burns completely before it goes up and out of your home's chimney or exhaust vent.