Find the cold air return vent in the ceiling that's closest to your wood furnace. Since most furnaces are installed in the basement, the ductwork should be easy to access. Unscrew the vent cover from the duct.
Install the square sheet metal duct over the warm air outlet on the furnace, securing with metal screws. Measure the distance from the furnace to the cold air return and connect sections of duct work to fit the distance.
Connect the ducts with duct tape at each intersection and slide the end section into the cold air return.
Turn on your circulating fan that came with your primary heating system. This will pull the warm air from the wood furnace into the rest of the house.
Install a standard air filter into the opening to clean the air entering the ventilation system. You don’t want any smoke wafting through your whole house.