Exterior wood furnaces, also known as outdoor wood furnaces or boilers, offer an efficient and eco-friendly way to heat your home. In this article, we’ll provide a concise yet comprehensive look at exterior wood furnaces, covering their technical details and proper operation.
Technical Details
1. Structure and Components:
Exterior wood furnaces consist of a firebox enclosed in a durable, weather-resistant casing. They often include a water jacket surrounding the firebox.
A chimney or exhaust stack expels combustion gases, while a water pump circulates hot water or a water-antifreeze mixture to the indoor heating system.
Most models have a thermostat control for regulating the heat output.
2. Fuel Source:
These furnaces are designed to burn wood, which can include logs, wood chips, or pellets. Some models can also burn coal.
A large combustion chamber accommodates substantial wood loads, reducing the need for frequent refueling.
3. Efficiency:
Exterior wood furnaces are highly efficient, often exceeding 90% combustion efficiency. They utilize wood’s energy content effectively to heat your home and water.
The water jacket surrounding the firebox captures additional heat, which is transferred to the indoor heating system.
4. Installation:
Installation typically involves connecting the furnace to your home’s heating system. This may include radiant floor heating, baseboard radiators, or forced-air systems.
Proper installation is critical for safety and efficiency. It’s advisable to hire a professional installer familiar with local building codes.
5. Fuel Storage:
- These systems require a dedicated wood storage area, often in the form of a woodshed or silo. Proper storage is essential to ensure the wood remains dry and ready for combustion.
Proper Operation
1. Fuel Selection:
Choose seasoned, dry wood with low moisture content. Wet or green wood can reduce combustion efficiency and create more creosote, a fire hazard.
Wood should be split to an appropriate size, usually 3-6 inches in diameter, to fit easily into the combustion chamber.
2. Loading and Ignition:
Load the furnace with wood, leaving enough space for proper air circulation and combustion.
Ignite the wood using kindling and fire starters. Once a good fire is established, close the door.
3. Temperature Control:
- Adjust the thermostat to regulate the water temperature and heat output.
4. Maintenance:
Regular maintenance is crucial. This includes cleaning the combustion chamber, removing ash, and inspecting for any signs of wear or damage.
Check the water level regularly to ensure proper circulation.
5. Safety:
Install a quality chimney and ensure it complies with local regulations.
Maintain proper clearances from combustible materials, including the furnace’s exterior.
Conclusion
Exterior wood furnaces offer an efficient and sustainable heating solution. By understanding their technical details and adhering to proper operation and maintenance, you can harness the power of wood to heat your home economically and ecologically. If considering an exterior wood furnace, consult with a professional installer to ensure a safe and efficient setup.