Wood-Burning Furnaces: Pros & Cons

Both have advantages and disadvantages in terms of ease of use, efficiency, durability and heat output. The type of furnace you choose will depend on the structure, design and size of your home. Consider the pros and cons of each option before upgrading to a wood-burning furnace.

Outdoor Wood Furnace Pros

Outdoor wood furnaces have a water jacket surrounding the inner fire box. The fire heats the water and a pump carries it through pipes into radiators or a forced-air heat exchanger inside your home. Outdoor burners distribute heat more evenly throughout your home than a wood stove placed in a single room. Outdoor wood-burning furnaces are often much larger than their indoor counterparts. They have a much higher capacity and the wood need not be split into small pieces. Wet and unseasoned wood will still burn efficiently because of the higher heat involved in much larger fires. A single outdoor wood-burning unit can heat garages, outbuildings and water for domestic use. There is almost no chance of fire spreading to your home from an outdoor burner and you never have to clean up ashes, bark, dirt and debris from hauling wood indoors.

Outdoor Wood Furnace Cons

Outdoor wood-burning furnaces inevitably produce a high volume of smoke. You can install a tall chimney to help disperse the smoke, but if you have nearby neighbors, constant smoke may be bothersome. Remember that you will have to load wood into an outdoor furnace at least twice a day during cold fall and winter months. This will remain a constant chore. You must also designate a large space for storing the massive amount of wood needed to run your stove for the entire cold season. You are completely responsible to purchase, transport, stack and store your wood. Burning wood produces a lot of ash, which you will need to clean out periodically to keep your furnace burning at the highest efficiency possible. Some states and jurisdictions have laws restricting the amount of smoke you can legally produce.

Indoor Wood Furnace Pros

Indoor wood furnaces and wood stoves burn wood at a higher efficiency than their outdoor counterparts. Indoor wood stoves and wood-burning furnaces burn at 70 to 80 percent efficiency, while outdoor wood burners only reach about 50 to 60 percent. Higher efficiency means more complete combustion and a lot less smoke than outdoor burners. Indoor stoves almost all come with a glass window so you can enjoy watching the fire and keep it burning just right. Wood stoves and furnaces will continue to keep your house warm during electricity or gas outages, and the price of wood remains consistently lower than gas or electricity.

Indoor Wood Furnace Cons

Indoor wood stoves and wood-burning furnaces require you to split wood into pieces small enough to fit into the stove. The small capacity of most indoor wood furnaces requires you to add wood many times throughout the day and night to maintain a consistent level of heat. You must feel comfortable hauling wood every day to heat your home. You must provide dry storage space for enough wood to last throughout the winter. Indoor wood-burning stoves generate a lot of ash, dirt and debris that you will have to clean up every day. Installation can be quite costly and you may need to install radiators and piping throughout your home to allow a single wood-burning unit to heat every room evenly.