Our house has a built-in meat smoker at the bottom of the chimney stack. I have no idea how to make this work! Basically, in the basement by the sauna are two doors that look a lot like ash-trap doors. I think you're supposed to build a fire in the one below and smoke food in the one above--there's a kind of grill in there already. You can adjust the airflow by turning a dial-like air intake on the front of the lower one. Has anyone seen/used these?